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19-4807; Rev 0; 7/09
0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
General Description
The MAX16064 is a fully integrated 4-channel digital power-supply controller and monitor IC that can be connected up to four power supplies to provide complete digital configurability. By interfacing to the power-supply reference input or feedback node, and the output enable, the MAX16064 takes control of the power supply to provide tracking, soft-start, sequencing, margining, and dynamic adjustment of the output voltage. Power-supply sequencing can be performed autonomously or controlled over the PMBusTM interface. Sequencing is controlled during power-down as well as power-up. Multiple MAX16064s can be combined to autonomously sequence more supplies. The sequencing order is stored in an external configuration EEPROM so sequence order changes can be reprogrammed without changing the PCB layout. The MAX16064 features an internal temperature sensor providing an additional level of system monitoring. Other features include a reset output and an SMBusTM alert output. Each channel of the MAX16064 includes an accurate 12-bit analog-to-digital converter (ADC) input and a differential amplifier for accurately monitoring and reporting the voltage at the load without being influenced by any difference in ground potentials. An integrated 12-bit digital-to-analog converter (DAC) can margin power supplies and dynamically adjust the output voltage using a closed-loop control system to provide an output-voltage accuracy of 0.3%. The user-programmable registers provide flexible and accurate control of time events such as delay time and transition period, monitoring for overvoltage and undervoltage, overtemperature fault and warning handling. The closed-loop operation is also programmable to make sure the MAX16064 works with any existing power supply to provide superior regulation accuracy and accurate margining. The MAX16064 operates using a PMBus-compliant communication protocol. The device can be programmed using this protocol or with a free graphic-user interface (GUI) available from the Maxim website that significantly reduces development time. Once the configuration is complete, the results can be saved into an EEPROM or loaded into the device through PMBus at power-up. This allows remote configuration of any power supply using the MAX16064, replacing expensive recalls or field service. The MAX16064 can be programmed with up to 114 distinct addresses to support large systems. The MAX16064 is offered in a space-saving, 36-pin, lead-free, 6mm x 6mm TQFN package and is fully specified from -40C to +85C.
Features
Accurate Voltage Output Control (AVOC) Controls Output Voltage with 0.3% Accuracy PMBus Interface for Programming, Monitoring, Sequencing Up and Down, and Margining Output Voltage and Temperature Monitoring with Adjustable Monitor Rate Programmable Soft-Start and Soft-Stop Ramp Rates Power-Supply Control using REFIN or FB Terminals Master-Slave Clocking Option Provides Accurate Timing Reference Across Multiple Devices External EEPROM Interface for Autoboot on Power-Up 3.0V to 3.6V Operating Voltage Range 6mm x 6mm, 36-Pin TQFN Package
MAX16064
Applications
Routers Servers Storage Systems Telecom/Networking DC-DC Modules and Power Supplies
Ordering Information
PART MAX16064ETX+ TEMP RANGE -40C to +85C PIN-PACKAGE 36 TQFN-EP*
+Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad.
Pin Configuration and Typical Operating Circuit appears at end of data sheet.
PMBus is a trademark of SMIF, Inc. SMBus is a trademark of Intel Corp.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
ABSOLUTE MAXIMUM RATINGS
AVDD, DVDD to AGND ............................................-0.3V to +4V AVDD to DVDD......................................................-0.3V to +0.3V AGND to DGND.....................................................-0.3V to +0.3V AGND1 to DGND...................................................-0.3V to +0.3V RS_+, RS_- to AGND................................................-0.3V to +6V RS_C, A1/SCLE, A2/SDAE, A3/CONTROL to AGND ......................-0.3V to (AVDD + 0.3V) RESET, SMBALERT, ENOUT_ to AGND...................-0.3V to +6V SCL, SDA to DGND ..................................................-0.3V to +4V DACOUT_, EN, CLKIO, REFO to AGND.....-0.3V to (AVDD + 0.3V) DACOUT_ Current ..............................................................10mA SDA Current ........................................................-1mA to +50mA Input/Output Current (all other pins) ...................................20mA Continuous Power Dissipation (TA = +70C) 36-Pin 6mm x 6mm TQFN (derate 35.7mW/C above +70C) .............................2857mW Thermal Resistance (Note 1) JA ................................................................................28C/W JC ..................................................................................1C/W Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VAVDD = VDVDD = 3.0V to 3.6V, VEN = 2V, VRS_+ - VRS_- = 2V, VRS_- = 0V, TA = TJ = -40C to +85C, unless otherwise specified. Typical values are at VAVDD = VDVDD = 3.3V, TA = +25C.) (Note 2)
PARAMETER AVDD/DVDD Operating Voltage Range AVDD Undervoltage Lockout (AVDD Rising) AVDD Undervoltage Lockout Hysteresis AVDD and DVDD Total Supply Current OUTPUT-VOLTAGE SENSING Voltage Regulation Accuracy (2V Range) TA = +25C, VRS_+ = 1.0V, VRS_- = 0V TA = -40C to +85C, VRS_+ = 1.0V, VRS_- = 0V TA = +25C, VRS_+ = 2.5V, VRS_- = 0V TA = -40C to +85C, VRS_+ = 2.5V, VRS_- = 0V -4 -6 -11 -16.5 0 -250 2V range, VRS_+ = -0.25V to +2V 5.5V range, VRS_+ = -0.25V to +5.5V 2V or 5.5V range, VRS_- = -0.25V to +0.25V -20 -20 -20 +4 +6 +11 +16.5 5.5 +250 +20 +100 0 mV mV mV mV V mV A A VUVLO VUVLO-HYS VRS_+ = VRS_- = 0V SYMBOL CONDITIONS MIN 3.0 2.75 2.8 100 12 18.5 TYP MAX 3.6 2.95 UNITS V V mV mA
Voltage Regulation Accuracy (5.5V Range) RS_+, RS_- Differential Mode Range RS_- to GND Differential Voltage RS_+ Input Bias Current RS_- Input Bias Current
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = VDVDD = 3.0V to 3.6V, VEN = 2V, VRS_+ - VRS_- = 2V, VRS_- = 0V, TA = TJ = -40C to +85C, unless otherwise specified. Typical values are at VAVDD = VDVDD = 3.3V, TA = +25C.) (Note 2)
PARAMETER Temperature Sensing Accuracy INTERNAL OSCILLATOR Frequency ADC Resolution INTERNAL REFERENCE Reference Voltage DAC Resolution Differential Nonlinearity Maximum Output-Voltage Range Capacitive Load Output-Voltage Slew Rate DAC Output Resistance DAC Driving Capability DAC Output Leakage Current CLKIO Input Logic-Low Voltage Input Logic-High Voltage Input Bias Current Input Clock Duty Cycle Output Low Voltage Output High Leakage CLKIO Pullup Voltage CLKIO Input Frequency Range CLKIO Output Frequency ENABLE INPUT (EN) EN Falling Threshold Voltage EN Rising Threshold Voltage EN Input Leakage Current OUTPUTS (ENOUT_, RESET, SMBALERT) Output Low Voltage Output Leakage VOL ISINK = 10mA VAVDD = VDVDD = 1.1V, ISINK = 100A VENOUT_ = 5V, 0V -1 0.4 0.4 +1 V V A VEN_TH 1.17 1.175 -0.25 1.21 1.23 1.23 1.281 +0.25 V V A fEXT_CLK 100 1 CLKIO in output mode, ISINK = 4mA VCLKIO = 3.6V -1 VCLKIO = 3.6V or 0V 2.1 -1 50 0.4 +1 3.6 1000 +1 0.8 V V A % V A V kHz MHz DAC output > 100mV; output error < 25mV DAC output switch open, VDACOUT_ = VREF or 0V -1 -250 DNL No load -2.5 VREF 1 LSB 200 0.35 10 +1 +250 12 +2.5 Bits LSB V pF V/s mA nA VREF TA = +25C 2.048 V 12 Bits 7.6 8 8.4 MHz SYMBOL CONDITIONS TA = 0C to +85C MIN TYP 3 MAX UNITS C INTERNAL TEMPERATURE SENSOR
MAX16064
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
ELECTRICAL CHARACTERISTICS (continued)
(VAVDD = VDVDD = 3.0V to 3.6V, VEN = 2V, VRS_+ - VRS_- = 2V, VRS_- = 0V, TA = TJ = -40C to +85C, unless otherwise specified. Typical values are at VAVDD = VDVDD = 3.3V, TA = +25C.) (Note 2)
PARAMETER Input Logic-Low Voltage Input Logic-Low Hysteresis Input Logic-High Voltage Input Logic-High Hysteresis Input Leakage Current SMBus INTERFACE (SCL, SDA) (Note 3) SCL, SDA Input Low Voltage SCL, SDA Input High Voltage SCL, SDA Input Leakage Current (Per Pin) Input Capacitance SCL, SDA Output Low Voltage SMBUS TIMING Serial-Clock Frequency Bus Free Time Between STOP and START Condition START Condition Setup Time START Condition Hold Time STOP Condition Setup Time Clock Low Period Clock High Period Data Setup Time Output Fall Time Data Hold Time Pulse Width of Spike Suppressed SMBus Timeout OTHER TIMING PARAMETERS PMBus Command Response Time Fault Response Time Recovery Time After Device Reset tPMB_RSP tFAULT_RSP tRST_WAIT 300 5 15 s ms s fSCL tBUF tSU:STA tHD:STA tSU:STO tLOW tHIGH tSU:DAT tOF tHD:DAT tSP tTIMEOUT SMBCLK time low for reset 25 CBUS = 10pF to 400pF From 50% SCL falling to SDA change 300 30 55 10 4.7 4.7 4.0 4.0 4.7 4.0 250 300 100 kHz s s s s s s ns ns ns ns ms CIN VOL ISINK = 3mA VIL VIH Input voltage falling Input voltage rising Device powered or unpowered, VAVDD = 0V to 3.6V, VSCL = VSDA = 0 or VAVDD 2.1 -1 10 0.4 +1 0.8 V V A pF V -12 VAVDD - 0.4 50 +12 50 SYMBOL CONDITIONS MIN TYP MAX 0.3 UNITS V mV V mV A ADDRESS PINS (A1/SCLE, A2/SDAE, A3/CONTROL)
Note 2: 100% production tested at TA = +25C. Limits over temperature are guaranteed by design. Note 3: The MAX16064 supports SCL clock stretching.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
Typical Operating Characteristics
(VAVDD = VDVDD = 3.3V, TA = +25C, unless otherwise noted.)
TOTAL SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX16064 toc01
MAX16064
NORMALIZED EN THRESHOLD vs. TEMPERATURE
MAX16064 toc02
NORMALIZED RESET TIMEOUT PERIOD vs. TEMPERATURE
1.08 NORMALIZED RESET TIMEOUT 1.06 1.04 1.02 1.00 0.98 0.96 0.94 0.92 NORMALIZED AT TA = +25NC
MAX16064 toc03
20 TOTAL SUPPLY CURRENT (mA)
1.010 1.008 NORMALIZED EN THRESHOLD 1.006 1.004 1.002 1.000 0.998 0.996 0.994 0.992 NORMALIZED AT TA = +25NC
1.10
16
TA = -40NC
12
8 TA = +85NC 4
TA = +25NC
0 2.6 2.8 3.0 3.2 3.4 3.6 VAVDD = VDVDD (V)
0.990 -40 -15 10 35 60 85 TEMPERATURE (NC)
0.90 -40 -15 10 35 60 85 TEMPERATURE (NC)
UV_FAULT TO RESET RESPONSE
MAX16064 toc04
ENOUT_ OUTPUT LOW VOLTAGE vs. SINK CURRENT
MAX16064 toc05
POWER SUPPLIES OUTPUT ACCURACY vs. TEMPERATURE
POWER SUPPLIES OUTPUT ACCURACY (%) 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -0.5 -40 -15 10 35 60 85 VOUT0 = 5V VOUT1 = 3.3V VOUT3 = 1.1V VOUT2 = 1.8V
MAX16064 toc06
0.8 ENOUT_ OUTPUT LOW VOLTAGE (V) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 0 5 10 15 20 25 30 35
0.5
5V VOUT0 2V/div
3.3V RESET 2V/div
1ms/div
40
ISINK (mA)
TEMPERATURE (NC)
ENOUT_WITH AVDD = DVDD RISING
MAX16064 toc07
ENOUT_ WITH AVDD = DVDD FALLING
MAX16064 toc08
AVDD = DVDD RISING 3.3V/ms
AVDD = DVDD 1V/div
AVDD = DVDD 1V/div
ENOUT1,2,3,4 2V/div 200ms/div 400Fs/div
ENOUT1,2,3,4 2V/div
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Typical Operating Characteristics (continued)
(VAVDD = VDVDD = 3.3V, TA = +25C, unless otherwise noted.)
REFIN MODE SOFT-START WITH SEQUENCING REFIN MODE SOFT-STOP WITH SEQUENCING
MAX16064 toc09
MAX16064 toc10
VOUT0 = 5V VOUT1 = 3.3V VOUT2 = 1.8V
VOUT0 = 5V VOUT1 = 3.3V VOUT2 = 1.8V VOUT3 = 1.1V
VOUT3 = 1.1V
2ms/div
2ms/div
REFIN MODE SOFT-STOP WITH TRACKING
MAX16064 toc11
REFIN MODE OPERATION OFF WITH SEQUENCING
MAX16064 toc12
VOUT0 = 5V
VOUT0 = 5V
VOUT1 = 3.3V VOUT2 = 1.8V VOUT3 = 1.1V
VOUT1 = 3.3V VOUT2 = 1.8V VOUT3 = 1.1V
2ms/div
40ms/div
REFIN MODE SOFT-START FROM A3 WITH SEQUENCING
REFIN MODE SOFT-STOP FROM A3 WITH SEQUENCING
A3/CONTROL 5V/div VOUT0 = 5V
MAX16064 toc13
MAX16064 toc14
A3/CONTROL 5V/div VOUT0 = 5V
VOUT1 = 3.3V VOUT2 = 1.8V VOUT3 = 1.1V
VOUT1 = 3.3V VOUT2 = 1.8V VOUT3 = 1.1V
2ms/div
2ms/div
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
Typical Operating Characteristics (continued)
(VAVDD = VDVDD = 3.3V, TA = +25C, unless otherwise noted.)
REFIN MODE MARGINING 500mV HIGH AT 1mV/s REFIN MODE MARGINING 500mV LOW AT 1mV/s
MAX16064
MAX16064 toc15
MAX16064 toc16
5V VOUT0 1V/div
4.5V
VOUT0 1V/div
0.6V VDACOUT0 200mV/div
0.54V
VDACOUT0 200mV/div
400Fs/div
400Fs/div
FB MODE MARGINING HIGH FROM 5V TO 5.5V
MAX16064 toc17
FB MODE MARGINING LOW FROM 5V TO 4.5V
MAX16064 toc18
5V
VOUT0 1V/div
5V
VOUT0 1V/div VDACOUT0 200mV/div
0.6V VDACOUT0 200mV/div
0.6V
400ms/div
400ms/div
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Pin Description
PIN 1 2 3 4 5 6 7 8 9 NAME RS2RS2+ RS3+ RS3RS3C EN DACOUT1 AGND ENOUT0 FUNCTION Differential Remote-Sense Input 2 Return of the DC-DC Output Voltage. Connect to the return terminal at the load. Differential Remote-Sense Input 2 of DC-DC Output Voltage. Connect to the load terminal where the output must be regulated. Differential Remote-Sense Input 3 of DC-DC Output Voltage. Connect to the load terminal where the output must be regulated. Differential Remote-Sense Input 3 Return of the DC-DC Output Voltage. Connect to the return terminal at the load. Filter Capacitor for VSENSE Amplifier 3. Connect a 1F capacitor from RS3C to AGND. Enable Input. All ENOUT_ are deasserted when the voltage on EN is below 1.2V (typ). Used to turn on/off the controlled power supplies in conjunction with the PMBus OPERATION command. Analog Voltage Output of Internal 12-Bit DAC 1. Connect to TRIM, REFIN, or FB of a DC-DC module or an LDO to adjust the power-supply output voltage. High impedance in shutdown. Analog Ground. Connect AGND to AGND1 and to DGND externally close to the device. On/Off Signal Output 0. Typically used to turn on/off a power supply. Controlled by the PMBus OPERATION command or the sequencer. Can be configured as either an active-high or an active-low open-drain output. See the ENOUT_ Operation section. On/Off Signal Output 1. Typically used to turn on/off a power supply. Controlled by the PMBus OPERATION command or the sequencer. Can be configured as either an active-high or an active-low open-drain output. See the ENOUT_ Operation section. On/Off Signal Output 2. Typically used to turn on/off a power supply. Controlled by the PMBus OPERATION command or the sequencer. Can be configured as either an active-high or an active-low open-drain output. See the ENOUT_ Operation section. On/Off Signal Output 3. Typically used to turn on/off a power supply. Controlled by the PMBus OPERATION command or the sequencer. Can be configured as either an active-high or an active-low open-drain output. See the ENOUT_ Operation section. Clock Input/Output. User-configurable clock input/output signal. The system controller can provide a clock input to synchronize the time bases of multiple MAX16064 devices. Alternatively, a MAX16064 can provide a 1MHz output clock to other MAX16064s for synchronization. See the MFR_MODE (D1h) section. When configured as an output, CLKIO is an open-drain output and a pullup resistor is required. Dual-Functioned MAX16064 Slave Address Identifier (LSB) and EEPROM I2C Clock Output. See the MAX16064 Address Assignment and External EEPROM Interface sections. Dual-Functioned MAX16064 Slave Address Identifier and EEPROM I2C Data Input/Output. See the MAX16064 Address Assignment and External EEPROM Interface sections. Dual-Functioned MAX16064 Slave Address Identifier (MSB) and Power-Supply On/Off Control Using the MFR_MODE Command. See the MAX16064 Address Assignment and A3/CONTROL Operation sections. Active-Low, Open-Drain Reset Output
10
ENOUT1
11
ENOUT2
12
ENOUT3
13
CLKIO
14 15
A1/SCLE A2/SDAE
16 17
A3/CONTROL RESET
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
Pin Description (continued)
PIN 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 -- NAME SMBALERT SCL SDA DGND DVDD RSVD DACOUT3 AGND1 AVDD DACOUT2 RS1RS1+ RS1C REFO RS0+ RS0C RS0DACOUT0 RS2C EP SMBus Serial-Clock Input/Output SMBus Serial-Data Input/Output Digital Ground. Connect DGND to AGND and AGND1 externally close to the device. Digital Power-Supply Input. Connect a 1F capacitor from DVDD to DGND. Reserved. Connect to DVDD externally. Analog Voltage Output of Internal 12-Bit DAC 3. Connect to TRIM, REFIN, or FB of a DC-DC module or an LDO to adjust the power-supply output voltage. High impedance in shutdown. Analog Ground. Connect to AGND and DGND externally close to the device. Analog Power-Supply Input. Connect a 1F capacitor from AVDD to AGND. Analog Voltage Output of Internal 12-Bit DAC 2. Connect to TRIM, REFIN, or FB of a DC-DC module or an LDO to adjust the power-supply output voltage. High impedance in shutdown. Differential Remote-Sense Input 1 Return of the DC-DC Output Voltage. Connect to the return terminal at the load. Differential Remote-Sense Input 1 of DC-DC Output Voltage. Connect to the load terminal where the output must be regulated. Filter Capacitor for VSENSE Amplifier 1. Connect a 1F capacitor from RS1C to AGND. Reference Output. Connect a 1F capacitor from REFO to AGND. Differential Remote-Sense Input 0 of DC-DC Output Voltage. Connect to the load terminal where the output must be regulated. Filter Capacitor for VSENSE Amplifier 0. Connect a 1F capacitor from RS0C to AGND. Differential Remote-Sense Input 0 Return of the DC-DC Output Voltage. Connect to the return terminal at the load. Analog Voltage Output of Internal 12-Bit DAC 0. Connect to TRIM, REFIN, or FB of a DC-DC module or an LDO to adjust the power-supply output voltage. High impedance in shutdown. Filter Capacitor for VSENSE Amplifier 2. Connect a 1F capacitor from RS2C to AGND. Exposed Pad. Internally connected to AGND. Connect EP to the ground plane of the power supplies for best temperature measurement performance. FUNCTION Active-Low, Open-Drain Fault-Detection Interrupt Output
MAX16064
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
AVDD DVDD RSVD REFO
RS0+ CLK0 RS0RS0C RS1+ REF 12-BIT VOUT DAC 0 S0 DACOUT0 ENOUT0
RS1RS1C RS2+
VOLTAGE SCALING AND MUX
ENOUT1 12-BIT ADC (SAR) DIGITAL COMPARATORS AND SEQUENCER 12-BIT VOUT DAC 1 S1 DACOUT1
ENOUT2 12-BIT VOUT DAC 2 S2 DACOUT2
RS2RS2C RS3+ INTERNAL TEMP SENSOR 12-BIT VOUT DAC 3
ENOUT3 S3 DACOUT3
RS3RS3C EN
RESET
1.2V PMBus DEFAULT MEMORY (EXTERNAL EEPROM) PAGE 0 PAGE 1 PAGE 2 PAGE 3 PAGE 0 PMBus OPERATING MEMORY PAGE 1 PAGE 2 PAGE 3
PMBus CONTROL EXTERNAL EEPROM INTERFACE I2C SMBus INTERFACE
MAX16064
A1/SCLE
A2/SDAE
A3/CONTROL
SCL
SDA
SMBALERT
DGND
AGND
AGND1
Figure 1. MAX16064 Functional Diagram
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
Detailed Description
The MAX16064 adds digital control functionality to four power supplies. Using a closed-loop control system, the MAX16064 can continuously adjust the power-supply output voltages to maintain 0.3% output-voltage accuracy. The MAX16064 can also be programmed to sequence, track, and margin each power supply. A PMBus-compliant interface bus provides access to configuration parameters of the MAX16064, including monitoring thresholds, sequence delays, soft-start and soft-stop slew rates, output-voltage settings, an on-chip temperature sensor, and more. Up to 114 MAX16064s can reside on the same PMBus bus, each controlling its own power supplies, under commands from the PMBus system controller, as shown in Figure 2. The MAX16064s can be placed close to the power supplies they control so that all sensitive analog traces are short and less susceptible to noise. The power supplies can also be placed close to the load where they provide the best transient response and lowest losses with short power plane runs.
MAX16064
RS0+ RS0DACOUT0 ENOUT0 MAX16064 SCL SYSTEM CONTROLLER SDA IRQ RST SCL SDA SMBALERT RESET RS1+ RS1DACOUT1 ENOUT1 RS2+ RS2DACOUT2 ENOUT2 RS3+ RS3DACOUT3 ENOUT3
VO+ VOFB EN VO+ VOFB EN VO+ VOFB EN VO+ VOFB EN
POWER SUPPLY 0
POWER SUPPLY 1
POWER SUPPLY 2
POWER SUPPLY 3
RS0+ RS0DACOUT0 ENOUT0 MAX16064 SCL SDA SMBALERT RESET RS1+ RS1DACOUT1 ENOUT1 RS2+ RS2DACOUT2 ENOUT2 RS3+ RS3DACOUT3 ENOUT3
VO+ VOFB EN VO+ VOFB EN VO+ VOFB EN VO+ VOFB EN
POWER SUPPLY (N-3)
POWER SUPPLY (N-2)
POWER SUPPLY (N-1)
POWER SUPPLY (N)
Figure 2. System Application Showing Multiple MAX16064s Controlling Power Supplies
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
MAX16064 Operating Modes
Reference Input (REFIN) Mode Figure 3 shows how to connect a MAX16064 to the reference voltage input of a typical power supply, allowing the MAX16064 to fully control the power-supply output voltage. Connect a DACOUT_ of the MAX16064 to the REFIN input of the power supply and connect the output-voltage terminals of the power supply to the RS_+ and RS_- sense inputs of the MAX16064. The sensed voltage on RS_+ and RS_- is filtered by an internal 200 resistor and an external capacitor connected to RS_C, and is digitized by a 12-bit ADC that uses an accurate internal reference voltage. Normal operation begins as follows: upon receiving an OPERATION ON command or a turn-on signal from A3/CONTROL, the MAX16064 waits the programmed t ON_DELAY time, then switches on the associated ENOUT_ output and ramps up the power-supply output voltage to its target VOUT_COMMAND value precisely in the programmed tON_RISE time. This facilitates easy implementation of tracking of multiple output rails. On reaching the target output voltage, the MAX16064 continuously monitors the power-supply output voltage obtained at the RS_+ and RS_- inputs, and regulates it to within 0.3% by incrementing or decrementing the DACOUT_ output 1 LSB (0.5mV) at a time. The MAX16064 output-voltage correction rate is controlled by MFR_MODE.1, VLTO, and DAC_ACT_CNT, as discussed in the ADC Conversion, Monitoring, and AVOC Adjustment Rates section. Once the requested target power-supply voltage is reached, it can be margined up or down at a slew rate programmed by the VOUT_TRANSITION_RATE parameter. To achieve this, the MAX16064 increments or decrements the DACOUT_ output in a suitable number of steps that depend on the programmed transition rate. The number of steps is calculated from the VOUT_SCALE_LOOP parameter, which must be set to the ratio of the power-supply output voltage to the power-supply reference voltage. This ratio is the same as the voltage-divider ratio implemented on the power supply from its output voltage node to the inverting input of its error amplifier. This allows the MAX16064 to correctly calculate the number of DACOUT steps and voltage increments/decrements per step and thus achieve the programmed rise time and transition time. Since the reference voltage input is provided by the MAX16064, the REFIN mode provides complete control of the power supply in terms of soft-start, soft-stop, and margining transitions.
Upon receiving an OPERATION OFF command or a turn-off signal from A3/CONTROL, the MAX16064 waits the programmed tOFF_DELAY time, ramps the output voltage down to zero in the programmed tOFF_FALL time, then deasserts the ENOUT_ output. Each of the four power-supply converters has its own set of delay parameters, so sequencing is accomplished by loading different delay times for each power supply.
Feedback (FB) Mode Some power-supply converters do not provide a reference input. In these applications, the feedback node can be used instead. Connect a DACOUT_ output of the MAX16064 to the feedback node (FB) through a resistor RFB as shown in Figure 5. In steady-state operation, the MAX16064 controls the power-supply voltage as measured between RS_+ and RS_- to 0.3% accuracy by adjusting DACOUT_ 1 LSB at a time (0.5mV), up and down as required. This mode of operation is termed FB mode. Since the MAX16064 does not have control over the power-supply error-amplifier reference voltage, this mode relies on the power-supply soft-start setting to implement the required soft-start time.
Upon receiving an OPERATION ON command or a turn-on signal from A3/CONTROL, the MAX16064 waits the programmed tON_DELAY time, turns on the ENOUT_ output, causing the power supply to ramp up its output voltage to its target value. The soft-start time taken by the power supply to ramp from zero to its commanded output voltage should be entered into the MAX16064 with the tON_RISE parameter. During tON_RISE, the MAX16064 maintains DACOUT_ in a high-impedance state by keeping the S_ switches open. This allows the voltage at DACOUT_ to equal that of the FB node of the power supply. At the end of the tON_RISE delay time, the internal DAC output voltage is set to match the external voltage measured on DACOUT_, and then the DACOUT_ switch S_ is closed. The voltages on either side of the resistor RFB should be equal, or very close to equal. Under these conditions, little or no current flows into the FB node from DACOUT_ and no perturbations are introduced to the output voltage. From this point on, the MAX16064 adjusts the voltage at DACOUT_ to provide accurate output-voltage control. In FB mode, the user must supply tON_DELAY and tON_RISE. If those parameters are not set (the default values are zero), S_ closes prematurely and causes the supply voltage to overshoot or undershoot.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
3.3V AVDD DVDD 1F RSVD AGND AGND1 DGND A1/SCLE A2/SDAE 200 A3/CONTROL REFO 1F S1 DACOUT1 ENOUT1 RS2RS2+ 200 SCL SDA SYSTEM CONTROLLER IRQ EN RESET SMBALERT ENOUT2 RS3RS3+ 200 RS3C VO+ S3 DACOUT3 ENOUT3 VOPOWER SUPPLY 3 VIN+ VINLOAD S2 DACOUT2 RS2C VO+ VOPOWER SUPPLY 2 VIN+ VINLOAD REFIN EN RS1RS1+ RS1C VO+ VOPOWER SUPPLY 1 VIN+ VINLOAD S0 DACOUT0 ENOUT0 REFIN EN POWER SUPPLY 0 200 MAX16064 RS0RS0+ RS0C VO+ VOVIN+ VINLOAD
REFIN EN
REFIN EN
Figure 3. Typical System Application--REFIN Mode
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
tPMB_RSP tON_DELAY tON_RISE tPMB_RSP tOFF_DELAY tON_FALL
PMBus
OPERATION ON
IDLE
OPERATION OFF
IDLE
ENOUT_
CLOSE S_ DAC OUTPUT
POWER-SUPPLY VOUT
POWER-SUPPLY OPERATION
TURN-ON
TURN-OFF
Figure 4. REFIN Mode Timing
After receiving an OPERATION OFF command or a turn-off signal from A3/CONTROL, the MAX16064 waits the programmed t OFF_DELAY time, deasserts the ENOUT_ output, and turns off the power supply. For the FB mode, use the following formula to calculate the value of RFB: RFB = R1 x VDAC VO
with an upper voltage divider resistor R1 = 10k, RFB is calculated as follows: RFB = 10k x (0.6V - 0.03V) = 57k 0.1V
This value of RFB allows the MAX16064 to margin the power-supply output voltage up by 10%. It is useful to check the margin low condition by using the formula: VO = R1 x VDAC (2.0V - 0.6V) = 10k x = 0.245V RFB 57k
Where R1 is the upper feedback divider resistor, VO is the required change in output voltage, and VDAC is the DACOUT output-voltage change that the user allows. The recommended operating range for the DACOUT_ voltage for power-supply output voltage adjustment is between 30mV and 2V. Note that VDAC is the difference between the steady-state power-supply FB node voltage, VFB, and the voltage limits on DACOUT_. This is best illustrated with an example as follows: Consider an application involving a power supply with VFB = 0.6V. Let the desired margining be 10% for a power-supply output voltage of 1V. For a power supply
The effective margining range for the 57k resistor therefore turns out to be between +10% and -24.5%. Note that the VOUT_TRANSITION_RATE parameter has no effect on FB mode. The transition time for margining in the FB mode of operation is a function of the update rate (fAVOC), see the MFR_DAC_ACT_CNT (E0h) section for the calculation of fAVOC. RFB and R1, and is given by the following formula: x VO x 2000 R tFB = FB fAVOC x R1
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
3.3V AVDD DVDD 1F RSVD AGND AGND1 DGND A1/SCLE A2/SDAE ENOUT0 RS1RS1+ A3/CONTROL REFO 1F S1 DACOUT1 RFB 200 RS1C R1 VO+ FB VOPOWER SUPPLY 1 VIN+ VINLOAD EN S0 DACOUT0 RFB 200 MAX16064 RS0RS0+ RS0C R1 VO+ FB VOPOWER SUPPLY 0 VIN+ VINLOAD
ENOUT1 RS2RS2+ 200 SCL SDA SYSTEM CONTROLLER IRQ EN RESET SMBALERT ENOUT2 RS3RS3+ 200 RS3C S2 DACOUT2 RFB RS2C
EN
LOAD R1 VO+ FB VOPOWER SUPPLY 2 VIN+ VIN-
EN
LOAD R1 VO+ VOPOWER SUPPLY 3 VIN+ VIN-
S3
FB DACOUT3 RFB
ENOUT3
EN
Figure 5. Typical System Application--Feedback Mode
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
tPMB_RSP tON_DELAY OPERATION ON tON_RISE OPERATION OFF tPMB_RSP tOFF_DELAY tOFF_FALL
PMBus
IDLE
IDLE
ENOUT_ CLOSE S_ OPEN S_
DAC OUTPUT
HIGH-Z tPS_RISE tPS_FALL
HIGH-Z
POWER-SUPPLY VOUT
POWER-SUPPLY OPERATION
TURN-ON
TURN-OFF
IN FB MODE, tPS_RISE AND tPS_FALL ARE NOT CONTROLLED BY THE MAX16064 AND ARE DEPENDENT ON POWER-SUPPLY IMPLEMENTATION.
Figure 6. Feedback Mode Timing
Temperature Sensing
To obtain useful temperature readings, place the MAX16064 in close proximity to the power supplies. The on-chip temperature sensor on the MAX16064 senses the temperature of the die, which is related to the exposed pad temperature of the MAX16064 by the junction-to-case thermal resistance. The exposed pad of the MAX16064 can connect to the heat dissipating ground plane of the power supplies, and the power supplies' boards can be characterized to obtain the relationship between the power supplies' temperature and temperature as measured by the MAX16064. This information can be used to set overtemperature fault settings in the MAX16064.
ADC Conversion, Monitoring, and AVOC Adjustment Rates
Several timing parameters control the rate at which the MAX16064 monitors voltages and temperatures and the rate at which the MAX16064 adjusts the power-supply output voltages. Each of the four voltage input channels
and the single temperature channel conversions are performed round-robin fashion. If the input filter is turned on by setting register MFR_MODE[1] to 0, then four conversions are performed for each channel instead of just one. A small programmable delay is inserted in between each conversion, determined by the MFR_VLTO register. This establishes the total conversion rate of the voltages and temperature. Smaller values of MFR_VLTO results in a higher sampling rate, and larger values of MFR_VLTO allow for more ADC settling time. The ADC conversion result registers are compared to the fault threshold registers at a rate that is independent of the total conversion rate. The value of register MFR_SAMPLE_RATE determines how frequently this comparison occurs. Using higher fault comparison rates increases glitch sensitivity, but slows the response time of the MAX16064 to PMBus commands. Using lower fault comparison rates makes the MAX16064 less sensitive to power-supply output voltage glitches.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
Finally, the AVOC system uses a separate control loop rate that is related to the total ADC conversion rate. The value of register MFR_DAC_ACT_CNT sets the number of total ADC conversion cycles (one cycle is a complete set of ADC conversions for 4 voltages and 1 temperature) that must occur before AVOC changes the DAC output voltage. Smaller values of MFR_DAC_ACT_CNT shorten the adjustment time. Larger values of MFR_DAC_ACT_CNT adjust the output voltage at much slower rates, reducing possible negative effects on the power-supply control loop. address (MFR_SET_ADDRESS) is a value other than 0x00, this overrides the slave address information previously set by the address A3:A1 pins. Table 1b shows the contents and addresses of the configuration information expected by the MAX16064. This information is for reference only. It is recommended to use a properly configured, working MAX16064 to save its state to the EEPROM and limit direct modifications to as few fields as possible (such as the slave address). Temperature and voltage values are stored in an internal representation, which is not the same as the format used by the corresponding PMBus commands. For details on the EEPROM internal representation, see Conversion Rules (Table 1a). For example, to store to the EEPROM PAGE 2 VOUT_COMMAND = 3.0V, m = 19995, b = 0, R = -1. First calculate the PMBUS command value, which is 5998. If the voltage range is 2V, no conversion is required. Hence write 17h to address 28 and 6Eh to address 29. If the voltage range is 5.5V, the stored EEPROM value = 5998/2.75 = 2181. So write 08h to address 28 and write 85h to address 29. Note that the conversion is automatically handled by the MAX16064 when it stores and loads configuration information.
MAX16064
External EEPROM Interface
The MAX16064 can communicate with an EEPROM attached to the A1/SCLE and A2/SDAE. The MAX16064 communicates to the EEPROM with an address byte of 1010 0000 for writing and 1010 0001 for reading. For the data values of 2 bytes, the most significant byte is stored in the lower address of the EEPROM, whereas the least significant byte is stored in the higher address of the EEPROM. Upon reset, the MAX16064 tests for the presence of a configuration EEPROM. It searches for the SIGNATURE bytes in the attached EEPROM. If the SIGNATURE bytes are present, it concludes that it has a valid configuration EEPROM and starts reading configuration information from the attached EEPROM. If the slave
Table 1a. Conversion Rules
READ (INTERNAL TO PMBus) TEMPERATURE VOLTAGE Subtract 3010 (decimal) from the PMBus value No conversion in 2V mode; multiply by 2.75 in 5.5V mode WRITE (PMBus TO INTERNAL) Add 3010 (decimal) to the PMBus value No conversion in 2V mode; divide by 2.75 in 5.5V mode
Table 1b. 16-Bit Words Stored in EEPROM
EEPROM ADDRESS 0 2 4 6 8 10 12 14 NAME MFR_FAULT_REASON MFR_MODE TEMPERATURE_PEAK MFR_FAULT_TEMP MFR_VOUT_PEAK MFR_VOUT_PEAK MFR_VOUT_PEAK MFR_VOUT_PEAK PAGE -- -- -- -- 0 1 2 3 0D4h Internal representation (voltage) PMBus COMMAND 0E2h 0D1h 0D6h 0E4h -- Must also match MFR_TICK_RELOAD Internal representation (temperature) Internal representation (temperature) NOTES
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 1b. 16-Bit Words Stored in EEPROM (continued)
EEPROM ADDRESS 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76-87 88 90 92 94 96 98 100 102 NAME MFR_FAULT_VOUT MFR_FAULT_VOUT MFR_FAULT_VOUT MFR_FAULT_VOUT VOUT_COMMAND VOUT_COMMAND VOUT_COMMAND VOUT_COMMAND TON_RISE TON_RISE TON_RISE TON_RISE TON_DELAY TON_DELAY TON_DELAY TON_DELAY VOUT_MARGIN_HIGH VOUT_MARGIN_HIGH VOUT_MARGIN_HIGH VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_MARGIN_LOW VOUT_MARGIN_LOW VOUT_MARGIN_LOW TOFF_FALL TOFF_FALL TOFF_FALL TOFF_FALL OT_FAULT_LIMIT MFR_SAMPLE_RATE Reserved (set to 0) MFR_FAULT_RESPONSE MFR_FAULT_RESPONSE MFR_FAULT_RESPONSE MFR_FAULT_RESPONSE MFR_FAULT_RETRY MFR_FAULT_RETRY MFR_FAULT_RETRY MFR_FAULT_RETRY PAGE 0 1 2 3 0 1 2 3 0 1 2 3 0 1 2 3 0 1 2 3 0 1 2 3 0 1 2 3 -- -- -- 0 1 2 3 0 1 2 3 0DAh -- 0D9h -- 4Fh 0D3h -- Internal representation -- -- 65h -- 26h Internal representation (voltage) 25h Internal representation (voltage) 60h -- 61h -- 21h Internal representation (voltage) 0E3h Internal representation (voltage) PMBus COMMAND NOTES
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 1b. 16-Bit Words Stored in EEPROM (continued)
EEPROM ADDRESS 104-115 116 118 120 122 124 126 128 130 132 134 136 138 140 142 144 146 148 150 152 154 156 158 160-175 176 178 180 182 184-199 200 202 204 206 208 210 212 214 MFR_DATE MFR_STATUS_WORD WRITE_PROTECT ON_OFF_CONFIG ON_OFF_CONFIG ON_OFF_CONFIG ON_OFF_CONFIG VOUT_SCALE_LOOP VOUT_SCALE_LOOP VOUT_SCALE_LOOP VOUT_SCALE_LOOP OT_WARN_LIMIT Reserved (set to 0) MFR_SET_ADDRESS Reserved (set to 0) TOFF_DELAY TOFF_DELAY TOFF_DELAY TOFF_DELAY VOUT_TRANSITION_RATE VOUT_TRANSITION_RATE VOUT_TRANSITION_RATE VOUT_TRANSITION_RATE Reserved (set to 0) MFR_MODE_OUTPUT MFR_MODE_OUTPUT MFR_MODE_OUTPUT MFR_MODE_OUTPUT Reserved (set to 0) MFR_RESET_DELAY MFR_RESET_OUTPUT Reserved (set to 0) MFR_TICK_RELOAD MFR_STATUS_WORD MFR_STATUS_WORD MFR_STATUS_WORD MFR_STATUS_WORD NAME PAGE -- -- -- 0 1 2 3 0 1 2 3 -- -- -- -- 0 1 2 3 0 1 2 3 0 0 1 2 3 -- -- -- -- -- 0 1 2 3 0D8h Set to 0 -- 0DDh 0E1h -- 0D1h -- -- -- -- -- 0DEh -- -- -- 27h -- 64h -- 51h -- 0DBh -- Internal representation (temperature) -- Low byte: I2C address, high byte: reserved -- 29h -- 02h -- PMBus COMMAND 9Dh 0D8h 10h -- Set to 0 -- NOTES
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 1b. 16-Bit Words Stored in EEPROM (continued)
EEPROM ADDRESS 216-237 238-255 256-297 298 300 302 304 306 308 310 312 314 316 318 320 322 324 326 328 330-509 510 MFR_SERIAL MFR_USERDATA_00 VOUT_OV_FAULT_LIMIT VOUT_UV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_OV_FAULT_LIMIT VOUT_UV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_OV_FAULT_LIMIT VOUT_UV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_OV_FAULT_LIMIT VOUT_UV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT Unused (set to 0) SIGNATURE (set to 4432h) NAME MFR_LOCATION PAGE -- -- -- 0 0 0 0 1 1 1 1 2 2 2 2 3 3 3 3 -- -- PMBus COMMAND 9Ch 9Eh 0B0h 40h 44h 42h 43h 40h 44h 42h 43h 40h 44h 42h 43h 40h 44h 42h 43h -- N/A -- -- -- Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) Internal representation (voltage) -- -- NOTES
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
Figure 7 shows how the MAX16064 interfaces to an external serial EEPROM using the A1/SCLE and A2/SDAE in applications where a master controller does not exist or is not required. Using the GUI, the user can select each MAX16064 device and configure all the required output-voltage settings and sequencing/tracking information. Once the configuration is complete, the results can be saved to the external EEPROM by using the STORE_DEFAULT_ALL command and configuration restored on the MAX16064 power-on reset. The EEPROM can also be preprogrammed prior to board assembly in the manufacturing environment. A3/CONTROL can be used as a control signal to turn on/off the power supply in a similar fashion as the OPERATION command. Use a serial EEPROM IC with a minimum of 4kb of storage to ensure proper device operation. PMBus system controller can monitor the power-supply health by issuing various inquiries and status commands to the MAX16064.
MAX16064
RESET Output Operation
RESET is an active-low, open-drain output that is low when the device is powering on. RESET is assigned to one of the power supplies using the MFR_RESET_OUTPUT command. When that power-supply output is at the target voltage, RESET goes high after the reset timeout period (see Figure 9). The reset timeout period (tRP) is set by the MFR_RESET_DELAY command. The MFR_RESET_OUTPUT value defines which powersupply output affects RESET. If MFR_RESET_OUTPUT is set to 0, 1, 2, or 3, then RESET goes high tRP after that output has reached its target value. If MFR_RESET_OUTPUT is any other value, RESET is permanently low. If the power-supply output selected by MFR_RESET_OUTPUT is later disabled for any reason (either due to a fault condition, or an OPERATION OFF command), then RESET goes low immediately. To enable faults on any power supply to cause RESET to go low, set the MFR_MODE_OUTPUT.GLOBALFAULTS bit to a 1 for all the supplies. RESET requires an external pullup resistor.
MAX16064 Operation
On power-up reset, the MAX16064 goes through an initialization process as shown in Figure 8. After initialization, the MAX16064 monitors the PMBus and executes the PMBus commands accordingly. In addition, if the power supply has been commanded to turn on, the MAX16064 also monitors the power-supply output voltage and temperature at the MFR_SAMPLE_RATE. The
3.3V
DVDD EEPROM 24LCXX VCC A1 A2 A3 GND 33k 33k RSVD 1F DGND MAX16064
AVDD 1F AGND
SCL SDA
A1/SCLE A2/SDAE
RS_RS_+ RS_C
LOAD
A3/CONTROL SYSTEM CONTROLLER SCL SDA RESET IRQ SMBALERT DACOUT_ ENOUT_ REFIN EN REFO 1F VO+ POWER SUPPLY VOVIN+ VIN-
Figure 7. Typical System Application with External EEPROM
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
RESET
INITIALIZE INTERNAL REGISTERS
SET PMBus ADDRESS ACCORDING TO A3:A1
VALID EEPROM? Y RESTORE CONFIGURATION FROM EEPROM
N
asserts to signal the PMBus master if any of the voltage or temperature fault has occurred. Typically, SMBALERT is connected to all other SMBALERT opendrain signals in the system, creating a wired-OR function with all SMBALERT outputs. When the master is interrupted by its SMBALERT input, it stops or finishes the current bus transfer and places an alert response address (ARA) on the bus. The slave that pulled the SMBALERT signal low acknowledges the ARA and places its own address on the bus, identifying itself to the master as the slave that caused the interrupt. SMBALERT deasserts when the MAX16064 responds to the ARA. SMBALERT deasserts when all the fault conditions are removed. SMBALERT is also cleared by the CLEAR_FAULTS command.
ENOUT_ Operation
When power is applied, all ENOUT_ are held low. Upon receiving a command to turn on the power supply, ENOUT_ goes high. The polarity can be changed by the ENOUT_POL bit of the MFR_MODE_OUTPUT command. Setting the bit to a 1 makes the ENOUT_ active low. If the bit in the external EEPROM is set to 1, upon power-up, the ENOUT_ is held low until the bit is copied from the EEPROM to the on-chip register at which time the ENOUT_ goes high. Upon receiving a command to turn on the power supply, ENOUT_ goes low. It takes 1.60ms (typ) to copy the configuration bits from the EEPROM to the on-chip registers.
INTERNAL REFERENCE STABLE? Y
N
ASSERT SMBALERT
Table 2. ENOUT_ Active State
ENOUT_ DEFAULT STARTUP STATE Low
N
ENABLE PMBus COMMUNICATION
MFR_MODE_OUTPUT. ENOUT_POL 0 1
ENOUT_ ACTIVE STATE Active high Active low
PMBus COMMAND?
Low
Y
EN Operation
The MAX16064 includes an enable input (EN) that controls all ENOUT_ signals in conjunction with the MFR_MODE command. Unless MFR_MODE.IGNORE_EN is set, a below-threshold level on EN prevents any ENOUT_ from turning on. Additionally, if the voltage at EN falls below the 1.2V (typ) threshold during OPERATION ON, the MAX16064 follows the fault action in MFR_FAULT_RESPONSE.EN. Figure 9 shows a typical sequencing with MFR_MODE.IGNORE_EN = 0.
EXECUTE PMBus COMMAND
Figure 8. MAX16064 Initialization
SMBALERT Output Operation
SMBALERT is an optional interrupt signal defined in Appendix A of the SMBus specification. The MAX16064 provides an output SMBALERT as this interrupt signal. SMBALERT is an active-low, open-drain output and it
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
RESET ENOUT3 ENOUT2 ENOUT1 ENOUT0 EN
tON0
tRP
tOFF0
tON1
tOFF1
tON2
tOFF2
tON3
tOFF3
NOTE: MFR_RESET_OUTPUT = 3
Figure 9. MAX16064 Typical Sequencing Timing
MAX16064 Address Assignment
The MAX16064 picks a slave address in one of the two ways described below: 1) Hardwired by A3:A2:A1. 2) Restored from EEPROM at power-on.
Address assignment order is shown in Figure 10. The MAX16064 reads A3:A2:A1 address pins upon device reset and determines its address according to Table 3.
Table 3. MAX16064 A3:A1 Slave Address Assignment
A3/CONTROL L L L L Z Z Z Z L L Z A2/SDAE L L Z Z L L Z Z L Z L A1/SCLE L Z L Z L Z L Z H H H ADDRESS (BITS 7-1) 40h 01h* 02h 03h 04h 05h 06h 07h 09h 0Bh 0Dh
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 3. MAX16064 A3:A1 Slave Address Assignment (continued)
A3/CONTROL Z L L Z Z L Z H H H H H H H H H A2/SDAE Z H H H H H H L L Z Z L Z H H H A1/SCLE H L Z L Z H H L Z L Z H H L Z H ADDRESS (BITS 7-1) 0Fh 12h 13h 16h 17h 1Bh 1Fh 24h 25h 26h 27h 2Dh 2Fh 36h 37h 3Fh
*The shaded addresses are not available if external EEPROM is attached.
The hardwired address pins give 3 3 = 27 address options. For example, to configure the MAX16064 to have a slave address of 010 0101 (25h), set A3:A2:A1 = H:L:Z. The MAX16064 also responds to the broadcast address (00h). If an EEPROM with valid SIGNATURE bytes is attached to the MAX16064, the MAX16064 tries to restore its slave address from the EEPROM. This overrides the address set by the address pins. This gives a total of 128 possible slave addresses. Note that there are 14 reserved addresses that are restricted by the PMBus specification and may not be used in PMBus systems. If the address bit 7 from the EEPROM is set to 1, this is an invalid address and the MAX16064 continues using the address set by the address pins. When an EEPROM is attached to A2/SDAE and A1/SCLE, these pins assume either a logic-high or a logic-low level, therefore, the resulting number of possible addresses set by the A3:A2:A1 pins in this scenario is 23 = 8. In addition, for the MAX16064 with an EEPROM attached, the system controller can change the MAX16064 slave address by sending the new address with the MFR_SET_ADDRESS command. However, the new address is not immediately effective. The new address must be stored to the EEPROM first using the STORE_DEFAULT_ALL command. Then, the
MAX16064 power must be cycled to start the address assignment procedure and recalls the new address from the EEPROM.
A3/CONTROL Operation
The A3/CONTROL input is utilized in combination with the A2 and A1 inputs to set the PMBus address when power is applied to the device. After the PMBus address detection, the A3/CONTROL input functions as the PMBus CONTROL input. The ON_OFF_CONFIG command determines whether the A3/CONTROL input affects the on/off behavior of the power supply. When A3/CONTROL is enabled by the ON_OFF_CONFIG command, a transition of A3/CONTROL from low to high turns the power supply on, as if the MAX16064 has received an OPERATION ON command. A transition of A3/CONTROL from high to low initiates a soft-off to the power supply, as if the MAX16064 has received an OPERATION OFF command (soft-off, with sequencing). The MAX16064 still responds to the PMBus OPERATION command while A3/CONTROL is enabled. To detect the A3/CONTROL input, the A3/CONTROL signal pulse width has to satisfy the tA3_LOW and tA3_HIGH requirements to be detected. See the ON_OFF_CONFIG (02h) section and Table 6 for more information.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
SET SLAVE ADDRESS ACCORDING TO A3:A1
POWER ON
POWER OFF
VALID EEPROM AND BIT7 STORED ADDRESS IN EEPROM IS NOT 1?
Y
RESTORE SLAVE ADDRESS FROM EEPROM
N
MFR_SET_ADDR?
Y
SLAVE ADDRESS UNCHANGED. STORE NEW ADDRESS TEMPORARILY.
N
SAVE TO EEPROM?
Y
SAVE NEW ADDRESS TO EEPROM
N
Figure 10. MAX16064 Address Assignment
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
The dual functionality of A3/CONTROL of the MAX16064 requires that the system enable signal be isolated from A3 until the address setting has been read and latched by the MAX16064. Figure 11 shows one implementation for the three possible states of the A3/CONTROL setting. In each case, the system enable signal (MAX16064_EN) is applied to the input of a three-state buffer whose output is kept in the highimpedance state by a control input signal (HIZ_EN) for a time period during which the MAX16064 reads and latches the A3/CONTROL address setting. After this period, the control signal HIZ_EN goes low and allows the system enable signal to be applied to the MAX16064 A3/CONTROL pin. After a t A3_LOW , the MAX16064_EN signal transitions from low to high and causes the MAX16064s to commence power-supply startup operations.
3.3V
MAX16064
PMBus Digital Interface
From a software perspective, the MAX16064 appears as a PMBus device capable of executing a subset of PMBus commands. A PMBus 1.0-compliant device uses the SMBus version 1.1 for transport protocol and responds to the SMBus slave address. In this data sheet, the term SMBus is used to refer to the electrical characteristics of the PMBus communication using the SMBus physical layer. The term PMBus is used to refer to the PMBus command protocol. The MAX16064 employs five standard SMBus protocols (Write Word, Read Word, Write Byte, Read Byte, and Send Byte (see Figures 12-15)) to program output voltage and warning/faults thresholds, read monitored data, and provide access to all manufacturer-specific commands.
33k MAX16064_EN MAX16064 A3 A2 A1 U1 REFO 1F HIZ_EN tRST_WAIT MAX16064_UVLO AVDD
HIZ_EN
REFO
MAX16064 A3 A2 A1 U2 REFO 1F
MAX16064_EN
A3/CONTROL
tA3_LOW
HIZ_EN PLACES U1, U2, AND U3 OUTPUTS IN HIGH-IMPEDANCE STATE WHEN ASSERTED. MAX16064 A3 A2 A1 REFO 1F U1, U2, AND U3 ARE NOT NECESSARY IF AN EEPROM IS ATTACHED TO A1/SCLE AND A2/SDAE. A1/SCLE, A2/SDAE ARE EITHER PULLED UP OR PULLED DOWN WITH 33k WHEN CONNECTED TO AN EEPROM.
U3
33k
Figure 11. Application Diagram with A3/CONTROL as Both Address and On/Off Control Signal
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
The MAX16064 supports the group command. The group command is used to send commands to more than one PMBus device. It is not required that all the devices receive the same command. However, no more than one command can be sent to any one device in one group command packet. The group command must not be used with commands that require receiving devices to respond with data, such as the STATUS_BYTE command. When the MAX16064 receives a command through this protocol, it immediately begins execution of the received command after detecting the STOP condition. The MAX16064 supports the PAGE command and uses it to select which individual channel to access. When the data word is transmitted, the lower order byte is sent first and the higher order byte is sent last. Within any byte, the most significant bit (MSB) is sent first and the least significant bit (LSB) is sent last. The MAX16064 SMBus interface supports Packet Error Checking (PEC). See the MFR_MODE (D1h) section.
MAX16064
WRITE BYTE FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SELECTS TO WHICH COMMAND PARAMETER TO WRITE A DATA 8 BITS DATA BYTE: DATA FOR THE COMMAND SET BY THE COMMAND BYTE A P
READ BYTE FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SELECTS FROM WHICH COMMAND PARAMETER TO READ A SR ADDR 7 BITS SLAVE ADDRESS: REPEATED DUE TO CHANGE IN DATA-FLOW DIRECTION R A DATA 8 BITS DATA BYTE: DATA FOR THE COMMAND SET BY THE COMMAND BYTE NA P
WRITE WORD FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SELECTS TO WHICH COMMAND PARAMETER TO WRITE A DATA0 8 BITS A DATA1 8 BITS A P
DATA BYTE: DATA FOR THE COMMAND SET BY THE COMMAND BYTE
READ WORD FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SELECTS FROM WHICH COMMAND PARAMETER TO READ A SR ADDR 7 BITS SLAVE ADDRESS: REPEATED DUE TO CHANGE IN DATA-FLOW DIRECTION R A DATA0 8 BITS A DATA1 8 BITS NA P
DATA BYTE: DATA FOR THE COMMAND SET BY THE COMMAND BYTE
SEND BYTE FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SEND COMMAND WITH NO DATA A P S = START CONDITION SR = REPEATED START CONDITION P = STOP CONDITION = SLAVE TRANSMISSION
Figure 12. SMBus Protocols
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
S ADDR1 7 BITS SLAVE ADDRESS OF DEVICE 1 W A CMD1 8 BITS COMMAND BYTE FOR DEVICE 1 A DATA0 8 BITS DATA BYTES FOR DEVICE 1 A DATA1 8 BITS A
SR
ADDR2 7 BITS SLAVE ADDRESS OF DEVICE 2
W
A
CMD2 8 BITS COMMAND BYTE FOR DEVICE 2
A
DATA 8 BITS
A
DATA BYTES FOR DEVICE 2
SR
ADDR3 7 BITS SLAVE ADDRESS OF DEVICE 3
W
A
CMD3 8 BITS COMMAND BYTE FOR DEVICE 3
A
DATA0 8 BITS
A
DATA1 8 BITS
A
DATA BYTES FOR DEVICE 3
SR
ADDRn 7 BITS SLAVE ADDRESS OF DEVICE n
W
A
CMDn 8 BITS
A
P
COMMAND BYTE FOR DEVICE n: NO DATA BYTE
S = START CONDITION SR = REPEATED START CONDITION P = STOP CONDITION = SLAVE TRANSMISSION
Figure 13. SMBus Group Command Protocol
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
WRITE BYTE FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SELECTS TO WHICH COMMAND PARAMETER TO WRITE A DATA 8 BITS DATA BYTE: DATA FOR THE COMMAND SET BY THE COMMAND BYTE A PEC 8 BITS A P
READ BYTE FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SELECTS FROM WHICH COMMAND PARAMETER TO READ A SR ADDR 7 BITS SLAVE ADDRESS: REPEATED DUE TO CHANGE IN DATAFLOW DIRECTION R A DATA 8 BITS DATA BYTES: DATA FOR THE COMMAND SET BY THE COMMAND BYTE A PEC 8 BITS NA P
WRITE WORD FORMAT S ADDR 7 BITS W A COMMAND 8 BITS COMMAND BYTE: SELECTS TO WHICH COMMAND PARAMETER TO WRITE READ WORD FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SELECTS FROM WHICH COMMAND PARAMETER TO READ A SR ADDR 7 BITS SLAVE ADDRESS: REPEATED DUE TO CHANGE IN DATAFLOW DIRECTION R A DATA0 8 BITS A DATA1 8 BITS A PEC 8 BITS NA P A DATA0 8 BITS A DATA1 8 BITS A PEC 8 BITS A P
DATA BYTES: DATA FOR THE COMMAND SET BY THE COMMAND BYTE
DATA BYTES: DATA FOR THE COMMAND SET BY THE COMMAND BYTE
SEND BYTE FORMAT S ADDR 7 BITS SLAVE ADDRESS W A COMMAND 8 BITS COMMAND BYTE: SEND COMMAND WITH NO DATA A PEC 8 BITS S = START CONDITION SR = REPEATED START CONDITION P = STOP CONDITION = SLAVE TRANSMISSION A P
Figure 14. SMBus Protocols with PEC
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
S ADDR1 7 BITS SLAVE ADDRESS OF DEVICE 1 WA CMD1 8 BITS COMMAND BYTE FOR DEVICE 1 A DATA0 8 BITS DATA BYTES FOR DEVICE 1 A DATA1 8 BITS A PEC1 8 BITS A
SR
ADDR2 7 BITS
WA
CMD2 8 BITS COMMAND BYTE FOR DEVICE 2
A
DATA0 8 BITS
A
DATA1 8 BITS
A
PEC2 8 BITS
A
SLAVE ADDRESS OF DEVICE 2
DATA BYTES FOR DEVICE 2
SR
ADDR3 7 BITS
WA
CMD3 8 BITS COMMAND BYTE FOR DEVICE 3
A
DATA0 8 BITS
A
DATA1 8 BITS
A
PEC3 8 BITS
A
SLAVE ADDRESS OF DEVICE 3
DATA BYTES FOR DEVICE 3
SR
ADDRn 7 BITS
WA
CMDn 8 BITS
A
PECn 8 BITS
A
P
SLAVE ADDRESS OF DEVICE n
COMMAND BYTE FOR DEVICE n: NO DATA BYTE
S = START CONDITION SR = REPEATED START CONDITION P = STOP CONDITION = SLAVE TRANSMISSION
Figure 15. SMBus Group Command Protocol with PEC
A tLOW SCL
B tHIGH
C
D
E
F
G
H
I
J
K
L
M
SDA tSU;STA tHD;STA tSU;DAT tHD;DAT F = ACKNOWLEDGE BIT CLOCKED INTO MASTER G = MSB OF DATA CLOCKED INTO MASTER H = LSB OF DATA CLOCKED INTO MASTER I = MASTER PULLS SDA LINE LOW tSU;STO tBUF J = ACKNOWLEDGE CLOCKED INTO SLAVE K = ACKNOWLEDGE CLEAR PULSE L = STOP CONDITION M = NEW START CONDITION
A = START CONDITION B = MSB OF ADDRESS CLOCKED INTO SLAVE C = LSB OF ADDRESS CLOCKED INTO SLAVE D = R/W BIT CLOCKED INTO SLAVE E = SLAVE PULLS SDA LINE LOW
Figure 16. SMBus Write Timing Diagram
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
A tLOW SCL B tHIGH C D E F G H I J K L M
SDA tSU;STA tHD;STA tSU;DAT tHD;DAT F = ACKNOWLEDGE BIT CLOCKED INTO MASTER G = MSB OF DATA CLOCKED INTO SLAVE H = LSB OF DATA CLOCKED INTO SLAVE I = SLAVE PULLS SDA LINE LOW tSU;STO tBUF J = ACKNOWLEDGE CLOCKED INTO MASTER K = ACKNOWLEDGE CLOCK PULSE L = STOP CONDITION, DATA EXECUTED BY SLAVE M = NEW START CONDITION
A = START CONDITION B = MSB OF ADDRESS CLOCKED INTO SLAVE C = LSB OF ADDRESS CLOCKED INTO SLAVE D = R/W BIT CLOCKED INTO SLAVE E = SLAVE PULLS SDA LINE LOW
Figure 17. SMBus Read Timing Diagram
PMBus Protocol Support
The MAX16064 supports a subset of the commands defined in the Power System Management Protocol Specification Part II - Command Language Revision 1.0. For detailed specifications and the complete list of PMBus commands, refer to Part II of the PMBus specification available at www.PMBus.org. The supported PMBus commands and the corresponding MAX16064 behavior are described in this document. All data values are represented in DIRECT format, unless otherwise stated. Whenever the resolution of the data is less than the number of bits required, data are right justified (only the lower bits are significant) and the higher order bits are zero-padded, unless otherwise stated. For example, for a 2-byte value where the MAX16064 only has 12-bit data to return, the MAX16064 returns data in the lower 12 bits and zeropads the upper 4 bits. Whenever the PMBus specification refers to the PMBus device, it is referring to the MAX16064 operating in conjunction with a power supply. While the command may call for turning on or off the PMBus device, the MAX16064 always remains on to continue communicating with the PMBus master and the MAX16064 transfers the command to the power supply accordingly.
Interpreting Received DIRECT Format Values
The host system uses the following equation to convert the value received from the PMBus device, in this case the MAX16064, into a reading of volts, degrees Celsius, or other units as appropriate: X= 1 Y x 10-R - b m
(
)
where X is the calculated, real world value in the appropriate units (V, C, etc.); m, the slope coefficient, is a 2-byte, two's complement integer; Y is a 2-byte, two's complement integer received from the PMBus device; b, the offset, is a 2-byte, two's complement integer; and R, the exponent, is a 1-byte, two's complement integer.
Sending a DIRECT Format Value
To send a value, the host must use the equation below to solve for Y: Y = (mX + b) x 10R where: Y is the 2-byte, two's complement integer to be sent to the unit; m, the slope coefficient, is the 2-byte, two's complement integer; X is a real world value, in units such as volts, to be converted for transmission; b is the offset, is the 2-byte, two's complement integer; and R, the exponent, is the decimal value equivalent to the 1 byte, two's complement integer.
31
Data Format
Voltage data for commanding or reading the output voltage or related parameters (such as the overvoltage threshold) are presented in DIRECT format. DIRECT format data is a 2-byte, two's complement binary value. DIRECT format data may be used with any command that sends or reads a parametric value. The DIRECT format uses an equation and defined coefficients to calculate the desired values. The coefficients used by the MAX16064 can be found in Table 4.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 4. MAX16064 PMBus Command Summary (Global commands are shaded; they are not dependent on the PAGE)
COMMAND CODE 00h 01h 02h 03h 10h 11h 12h 19h 20h 21h 25h 26h 27h 29h 40h 42h 43h 44h 4Fh 51h 60h 61h 64h 65h 78h 79h 7Ah 7Dh 7Eh 80h 8Bh 8Dh 98h 99h 9Ah 9Bh 9Ch 9Dh 9Eh B0h COMMAND NAME TRANSACTION TYPE R/W Byte R/W Byte R/W Byte Send Byte R/W Byte Send Byte Send Byte Read Byte Read Byte R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word R/W Word Read Byte R/W Word Read Byte Read Byte Read Byte Read Byte Read Word Read Word Read Byte Block Read Block Read Block Read Block R/W Block R/W Block R/W Block R/W R R R R R R R R/W R/W R/W R/W R/W R/W R/W R/W R R R R R R R R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W W W W W R R R PAGE 0-3 R/W R/W R/W W R/W W W R R W W W W W W W W W W W W 255 NO. OF BYTES 1 1 1 0 1 0 0 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 2 1 1 1 1 2 2 1 2 2 2 -- -- -- -- m b R
PMBus STANDARD COMMANDS PAGE OPERATION ON_OFF_CONFIG CLEAR_FAULTS WRITE_PROTECT STORE_DEFAULT_ALL RESTORE_DEFAULT_ALL CAPABILITY VOUT_MODE VOUT_COMMAND VOUT_MARGIN_HIGH VOUT_MARGIN_LOW VOUT_TRANSITION_RATE VOUT_SCALE_LOOP VOUT_OV_FAULT_LIMIT VOUT_OV_WARN_LIMIT VOUT_UV_WARN_LIMIT VOUT_UV_FAULT_LIMIT OT_FAULT_LIMIT OT_WARN_LIMIT TON_DELAY TON_RISE TOFF_DELAY TOFF_FALL STATUS_BYTE STATUS_WORD STATUS_VOUT STATUS_TEMPERATURE STATUS_CML STATUS_MFR_SPECIFIC READ_VOUT READ_TEMPERATURE_1 PMBUS_REVISION MFR_ID MFR_MODEL MFR_REVISION MFR_LOCATION MFR_DATE MFR_SERIAL MFR_USER_DATA_00 -- -- -- -- -- -- -- -- -- 19995 19995 19995 256 128 19995 19995 19995 19995 -7612 -7612 1 1 1 1 -- -- -- -- -- -- 19995 -7612 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0 0 0 0 0 0 0 0 0 335 335 0 0 0 0 -- -- -- -- -- -- 0 335 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -1 -1 -1 0 0 -1 -1 -1 -1 -3 -3 1 3 1 3 -- -- -- -- -- -- -1 -3 -- -- -- -- -- -- -- --
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 4. MAX16064 PMBus Command Summary (continued) (Global commands are shaded; they are not dependent on the PAGE)
COMMAND CODE D0h D1h D3h D4h D6h D8h D9h DAh DBh DDh DEh DFh E0h E1h E2h E3h E4h COMMAND NAME TRANSACTION TYPE R/W Word R/W Word R/W Word Read Word Read Word R/W Word R/W Word R/W Word R/W Byte R/W Word R/W Word R/W Byte R/W Byte R/W Byte R/W Word R/W Word R/W Word R/W R/W R/W R/W R/W R/W R/W W R R/W R/W R/W R/W W R/W R/W R W W PAGE 0-3 R/W R/W R/W R/W 255 NO. OF BYTES 2 2 2 2 2 2 2 2 1 2 2 1 1 1 2 2 2 m b R
MANUFACTURER-SPECIFIC COMMANDS MFR_SMB_LOOPBACK MFR_MODE MFR_SAMPLE_RATE MFR_VOUT_PEAK MFR_TEMPERATURE_PEAK MFR_STATUS_WORD MFR_FAULT_RESPONSE MFR_FAULT_RETRY MFR_SET_ADDRESS MFR_RESET_DELAY MFR_MODE_OUTPUT MFR_VLTO MFR_DAC_ACT_CNT MFR_RESET_OUTPUT MFR_FAULT_REASON MFR_FAULT_VOUT MFR_FAULT_TEMP -- -- -- 19995 7612 -- -- -- -- 1 -- -- -- -- -- -- -- -- -- -- 0 335 -- -- -- -- 0 -- -- -- -- -- -- -- -- -- -- -1 -3 -- -- -- -- 1 -- -- -- -- -- -- --
The following example demonstrates how the host can send and retrieve values from the MAX16064. From Table 4, the coefficients used in the following parameters are: VOUT_COMMAND: m = 19995, b = 0, R = -1 READ_VOUT: m = 19995, b = 0, R = -1 If a host wants to command the power supply to output a voltage of 3.0V, the corresponding VOUT_COMMAND value is: Y = (mX + b) x 10R Y = (19995 x 3.0 + 0) x 10-1 = 5998.5 (decimal) = 176Eh (hex) Conversely, if the host received a value of 176Eh on a READ_VOUT command, this is equivalent to: X=
X=
Power supplies and power converters generally have no way of knowing how their outputs are connected to ground. Within the power supply, all output voltages are most commonly treated as positive. Accordingly, all output voltages and output voltage-related parameters of PMBus devices are commanded and reported as positive values. It is up to the system to know that a particular output is negative if that is of interest to the system. All output voltage-related commands use 2 data bytes.
Fault Management and Reporting
For reporting faults/warnings to the host on a real-time basis, the MAX16064 asserts the open-drain SMBALERT pin and sets the appropriate bit in the STATUS_BYTE and MFR_FAULT_STATUS registers, respectively. On recognition of the SMBALERT assertion, the host or system manager is expected to poll the I2C bus to determine the device asserting SMBALERT. The host sends the SMBus Alert Response Address (0001100). The MAX16064 will ACK the SMBus Alert Response Address, transmit its slave address, and deassert SMBALERT. The system controller then
33
1 Y x 10-R - b m
(
)
1 176Eh x 10-(-1) - 0 = 59980 19995 = 2.999750 19995 which is within 0.0083% of 3.0V.
(
)
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
communicates with PMBus commands to retrieve the fault/warning status information from the MAX16064. The following status commands are supported: STATUS_BYTE STATUS_WORD STATUS_VOUT STATUS_TEMPERATURE STATUS_CML STATUS_MFR_SPECIFIC MFR_STATUS_WORD MFR_FAULT_REASON MFR_FAULT_VOUT MFR_FAULT_TEMP See the individual command sections for more details. Faults/warnings are cleared when any one of the following conditions occurs: * A CLEAR_FAULTS command is received. * OPERATION commands are received that turn off and on the power supplies or A3/CONTROL is toggled to turn off and then turn on the power supplies. * Bias power (AVDD, DVDD) to the MAX16064 is removed and then reapplied. The MAX16064 responds to fault conditions according to the Manufacturer Fault Response command (MFR_FAULT_RESPONSE). This command byte determines how the MAX16064 should respond to each particular fault. In addition, the MAX16064 responds to the following error conditions. 1) If the internal reference fails to operate, SMBALERT is asserted. To clear this fault, the MAX16064 must go through a device reset. 2) The MAX16064 responds to unsupported commands with a NACK. 3) When the host sends insufficient data (too few bytes), the MAX16064 sets the CML bit and asserts SMBALERT. 4) When the host sends too much data (too many bytes), the MAX16064 sets the CML bit and asserts SMBALERT. When a read request is issued to a write-only command, the read operation is aborted and no warning is issued.
PAGE (00h)
The MAX16064 can control up to four power supplies using one PMBus (I2C) address. Send the PAGE command with data 0 to 3 to select which power supply is affected by all following commands. Set the PAGE to 255 when it is desired that following commands affect all four power supplies. If, when PAGE = 255, the host sends a command code that is not a global command (any command in Table 4 that is not shaded), the MAX16064 sets the CML, error flag. An example would be to set the PAGE to 255 and then issue an OPERATION command to turn on all the power supplies at one time.
OPERATION (01h)
The OPERATION command is used to turn the power supply on and off in conjunction with ENOUT_ according to the ENOUT_ polarity select setup. The OPERATION command is also used to cause the power supply to set the output voltage to the upper or lower margin voltages. The power supply stays in the commanded operating mode until a subsequent OPERATION command or change in the state of A3/CONTROL (if enabled) instructs the power supply to change to another state. The valid OPERATION command byte values are shown in Table 5. The OPERATION command controls how the MAX16064 responds when commanded to change the output. When the command byte is 00h, the MAX16064 immediately turns the power supply off and ignores any programmed turn-off delay and fall time. When the command byte is set to 40h, the MAX16064 powers down according to the programmed turn-off delay and fall time. In Table 5, Act On Fault means that if an output overvoltage warning or output overvoltage fault is detected when the output is margined high, the MAX16064 treats this as a warning or fault and responds as programmed by the warning limit or fault response command. Similarly, if an output undervoltage warning or output undervoltage fault is detected when the output is margined low, the MAX16064 treats this as a qualified warning/fault event and responds as programmed by the warning/fault limit or fault response command. Any command value not shown in Table 5 is an invalid command. If the MAX16064 receives a data byte that is not listed in Table 5, then it may treat this as invalid data, declares a communications fault (set CML bit and assert SMBALERT), and responds as described in the Fault Management and Reporting section. The default OPERATION value is 00h.
PMBus Commands
A summary of the PMBus commands supported by the MAX16064 is described in Table 4.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 5. OPERATION Command Byte
COMMAND BYTE 00h 40h 80h 94h 98h A4h A8h POWER SUPPLY ON OR OFF Immediate off (no sequencing) Soft-off (with sequencing) On On On On On Margin off (nominal) Margin low (ignore fault) Margin low (act on fault) Margin high (ignore fault) Margin high (act on fault) MARGIN STATE -- --
ON_OFF_CONFIG (02h)
The ON_OFF_CONFIG command configures the combination of CONTROL input and serial bus commands needed to turn the power supply on and off. This indicates how the power supply is commanded when power is applied. The ON_OFF_CONFIG message content is described in Table 6.
CLEAR_FAULTS (03h)
The CLEAR_FAULTS command is used to clear any fault bits that have been set. This command clears all bits in the STATUS_BYTE and MFR_FAULT_STATUS registers simultaneously. It also deasserts SMBALERT. The CLEAR_FAULTS command does not cause a power supply that has latched off for a fault condition to
Table 6. ON_OFF_CONFIG Message Contents
BIT NUMBER [7:5] Sets the default to operate either any time power is present or for the on/off to be controlled by A3/CONTROL input and serial bus commands PURPOSE Reserved. Always returns 000. 0 = Power supply turns on (ENOUT goes high) any time power is present regardless of the state of the A3/CONTROL pin. 1 = Power supply is not turned on until commanded by the CONTROL pin and OPERATION command (as configured in bits [3:0]). 0 = Power supply ignores the on/off portion of the OPERATION command received from the serial bus. 1 = An operation command must be received to turn the power supply on. Depending on bit [2], the MAX16064 may require the A3/CONTROL input to be asserted for the power supply to be turned on (ENOUT asserted). 0 = Power supply ignores the A3/CONTROL input. On/off is only controlled by the OPERATION command. 1 = Power supply requires the A3/CONTROL input to be asserted to turn on the power supply. Depending on bit [3], the MAX16064 may require the OPERATION command to be received for the power supply to be turned on (ENOUT asserted). 0 = A3/CONTROL input is active low. Drive low to turn on the power supply. 1 = A3/CONTROL input is active high. Drive high to turn on the power supply. 0 = Use the configured turn off delay (TOFF_DELAY) and fall time (TOFF_FALL). 1 = Turn off the power supply as quickly as possible (deassert ENOUT). MEANING
4
3
Controls how the power supply responds to commands received over the serial bus
2
Configures how the power supply responds to the A3/CONTROL input
1
Polarity of the A3/CONTROL input
0
A3/CONTROL input action when commanding the power supply to turn off
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
restart. The status of ENOUT_ under fault conditions is not affected by this command and should change only if commanded through the OPERATION command or A3/CONTROL. If the fault is still present after the CLEAR_FAULTS command is executed, the fault bit is set again and the host is also notified by asserting SMBALERT. This command is write-only. There is no data byte for this command. This command is write-only. There is no data byte for this command. For information on EEPROM contents, see the External EEPROM Interface section.
RESTORE_DEFAULT_ALL (12h)
The RESTORE_DEFAULT_ALL command transfers the default configuration information from the external I2C EEPROM device attached to A1/SCLE and A2/SDAE to the user memory registers in the device. The RESTORE_DEFAULT_ALL command can only be executed when the power supply is off. Otherwise, a communication fault occurs (CML = 1) and SMBALERT asserts. If an error occurs during data transfer, SMBALERT asserts and the CML bit is set to 1. The STATUS_BYTE, STATUS_WORD and MFR_FAULT_STATUS values are not restored by the RESTORE_DEFAULT_ALL command. This command is write-only. There is no data byte for this command. For information on EEPROM contents, see the External EEPROM Interface section.
WRITE_PROTECT (10h)
The WRITE_PROTECT command is used to provide protection against accidental changes to the MAX16064 operating memory. All supported commands may have their parameters read, regardless of the WRITE_PROTECT settings. The WRITE_PROTECT message content is described in Table 7.
STORE_DEFAULT_ALL (11h)
The STORE_DEFAULT_ALL command instructs the MAX16064 to transfer the user memory configuration information to an external I2C EEPROM device (default memory) attached to A1/SCLE and A2/SDAE. If an error occurs during the transfer, SMBALERT asserts and the CML bit is set to 1. It is permitted to use the STORE_DEFAULT_ALL command while the power supply is operating. However, the MAX16064 is unresponsive to PMBus commands while transferring the configuration. ENOUT_ maintains its state.
CAPABILITY (19h)
The CAPABILITY command is used to determine some key capabilities of the MAX16064. The CAPABILITY command is read-only. The message content is described in Table 8.
Table 7. WRITE_PROTECT Message Contents
DATA BYTE VALUE 1000 0000 0100 0000 0010 0000 0000 0000 MEANING Disable all writes except the WRITE_PROTECT command. Disable all writes except the WRITE_PROTECT, OPERATION, and PAGE commands. Disable all writes except the WRITE_PROTECT, OPERATION, PAGE, ON_OFF_CONFIG, and VOUT_COMMAND commands. Enable writes for all commands (default)
Table 8. CAPABILITY Command Message Contents
BIT 7 6:5 4 3:0 DESRIPTION Packet error checking Maximum PMBus bus speed SMBALERT# Reserved MEANING 1 = Packet error checking is supported. Always returns a 1. 00 = Maximum supported bus speed is 100kHz. 1 = Device supports an SMBALERT# output and the SMBus ARA protocol. MAX16064 returns 0000.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
VOUT_MODE (20h)
The VOUT_MODE command is used to report the data format of the device. The MAX16064 uses the direct format for all the voltage-related commands. The value returned is 40h, indicating DIRECT data format. This command is read only. See Table 4 for the m, b, and R values for the various commands.
VOUT_TRANSITION_RATE (27h)
The VOUT_TRANSITION_RATE command sets the rate in mV/s at which the power-supply output voltage should change when the power supply is commanded to change among the margin high, margin low, and margin off (ON) OPERATION mode. This commanded rate of change does not apply when the power supply is commanded to turn on or off. In that case, tON_RISE and tOFF_FALL apply. The two data bytes are in DIRECT format. Valid values are from 0 to 128mV/s (FB mode) or 0.004 to 30mV/s (REFIN mode). The default VOUT_TRANSITION_RATE value is 0. When VOUT_TRANSITION_RATE is cleared to 0, VOUT_TRANSITION_RATE is ignored and the voltage output is not changed even when commanded by the OPERATION command. When VOUT_TRANSITION_RATE is set to 07FFFh, the voltage output is adjusted as quickly as possible. If a VOUT_TRANSITION_RATE parameter results in the DAC outputting an out of range value (valid range 0 to 4090) during transition, the CML flag is set and SMBALERT is asserted to issue a warning. The VOUT_TRANSITION_RATE command applies to REFIN mode only and is ignored in feedback mode.
MAX16064
VOUT_COMMAND (21h)
The VOUT_COMMAND command loads the MAX16064 with the voltage to which the power-supply output is to be changed when it is commanded to turn on using the OPERATION command or A3/CONTROL transition when enabled. Once the power supply is turned on, changing the VOUT_COMMAND has no effect on the power-supply output voltage. The MAX16064 only adjusts the power supply to the new VOUT_COMMAND voltage after receiving a new turn-on command. The two data bytes are in DIRECT format. Valid values are from 0 to 2.0V when the input range is 2.0V, and 0 to 5.5V when the input range is 5.5V. See the MFR_MODE_OUTPUT (DEh) section for more information. The default VOUT_COMMAND value is 00h.
VOUT_MARGIN_HIGH (25h)
The VOUT_MARGIN_HIGH command loads the MAX16064 with the voltage to which the power-supply output is to be changed when the OPERATION command is set to margin high. If the power supply is already operating at margin high, changing VOUT_MARGIN_HIGH has no effect on the output voltage. The MAX16064 only adjusts the power supply to the new VOUT_MARGIN_HIGH voltage after receiving a new margin high OPERATION command. The two data bytes are in DIRECT format. Valid values are the same as VOUT_COMMAND. The default VOUT_MARGIN_HIGH value is 00h.
VOUT_SCALE_LOOP (29h)
In applications where the VOUT is not equal to the voltage at REFIN, VOUT_SCALE_LOOP is used. For example, if REFIN expects a 0.6V input for a 3.3V output, VOUT_SCALE_LOOP = 0.6V/3.3V = 0.182. In applications where the power-supply output voltage is greater than the MAX16064 input range, the output voltage of the power supply is sensed through a resistive voltagedivider, as illustrated in Figure 16. The resistive voltagedivider reduces or scales the output voltage, VOUT. The PMBus commands specify the actual power-supply output voltages and not the input voltage to the control circuit. To allow the MAX16064 to map between the commanded voltage (such as 3.3V), and the voltage at the control circuit input (perhaps 3.3V divided down to match a reference voltage of 2.0V), the VOUT_SCALE_LOOP command is used. VOUT _ SCALE _ LOOP = R2 R1 + R2
VOUT_MARGIN_LOW (26h)
The VOUT_MARGIN_LOW command loads the MAX16064 with the voltage to which the power-supply output is to be changed when the OPERATION command is set to margin low. If the power supply is already operating at margin low, changing VOUT_MARGIN_LOW has no effect on the output voltage. The MAX16064 only adjusts the power supply to the new VOUT_MARGIN_LOW voltage after receiving a new margin low OPERATION command. The two data bytes are in DIRECT format. Valid values are the same as VOUT_COMMAND. The default VOUT_MARGIN_LOW value is 00h.
The two data bytes are in DIRECT format. Valid values are from 0 to 1.0. Note that due to m, b, r representation restriction, the supplied value is rounded off to multiples of 1/128. Therefore, to ensure optimum operation, circuit design should choose a value as close as possible to multiples of 1/128 to avoid rounding errors affect37
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
ing the VOUT_TRANSITION_RATE slew rate. Final accuracy of VOUT is assured by the closed-loop voltage control. This value is dimensionless. The default VOUT_SCALE_LOOP value is 00h. The VOUT_SCALE_LOOP command is ignored in feedback mode. which causes an output voltage high warning. This value is typically less than the output overvoltage threshold in VOUT_OV_FAULT_LIMIT. The two data bytes are in DIRECT format. Valid values are the same as the VOUT_COMMAND. The default VOUT_OV_WARN_LIMIT value is 00h. In response to the VOUT_OV_WARN_LIMIT being exceeded, the MAX16064: 1) Sets the OTHER bit in the STATUS_BYTE. 2) 3) 4) 5) 6) 7) 8) Sets the OTHER bit in the STATUS_WORD. Sets the VOUT bit in the STATUS_WORD. Sets the VOUT Overvoltage Warning bit in the STATUS_VOUT. Sets the OV_WARN bit in the STATUS_MFR_SPECIFIC register. Sets the OV_WARN bit in the MFR_STATUS_WORD register. Sets the OTHER bit in the MFR_STATUS_WORD. Notifies the host using SMBALERT assertion.
VOUT_OV_FAULT_LIMIT (40h)
The VOUT_OV_FAULT_LIMIT command sets the value of the output voltage measured across RS_+ and RS_-, which causes an output overvoltage fault. The two data bytes are in DIRECT format. Valid values are the same as VOUT_COMMAND. The default VOUT_OV_FAULT_LIMIT value is 00h. In response to the VOUT_OV_FAULT_LIMIT being exceeded, the MAX16064: 1) 2) 3) 4) 5) 6) Sets the VOUT_OV bit in the STATUS_BYTE. Sets the VOUT_OV bit in the STATUS_WORD. Sets bit 5 (low byte) and bit 7 (high byte) of the STATUS_WORD. Sets the VOUT Overvoltage Fault bit in the STATUS_VOUT. Sets the VOUT_OV bit in the MFR_STATUS_WORD register. Responds as specified by VOUT_OV_FAULT_ RESPONSE bits in the MFR_FAULT_RESPONSE register. Notifies the host through SMBALERT assertion.
VOUT_UV_WARN_LIMIT (43h)
The VOUT_UV_WARN_LIMIT command sets the value of the output voltage measured across RS_+ and RS_-, which causes an output-voltage low warning. This value is typically greater than the output undervoltage fault threshold in VOUT_UV_FAULT_LIMIT. This warning is masked until the output voltage reaches the programmed voltage at startup, and also during turn-off when the power supply is disabled. The two data bytes are in DIRECT format. Valid values are the same as VOUT_COMMAND. The default VOUT_UV_WARN_LIMIT value is 00h. In response to violation of the VOUT_UV_WARN_LIMIT, the MAX16064: 1) Sets the OTHER bit in the STATUS_BYTE. 2) Sets the OTHER bit in the STATUS_WORD. 3) Sets the VOUT bit in the STATUS_WORD. 4) Sets the VOUT Undervoltage Warning bit in the STATUS_VOUT register. 5) Sets the UV_WARN bit in the STATUS_MFR_SPECIFIC register. 6) 7) 8) Sets the UV_WARN bit in the MFR_STATUS_WORD register. Sets the OTHER bit in the MFR_STATUS_WORD. Notifies the host using SMBALERT assertion.
7)
VOUT_OV_WARN_LIMIT (42h)
The VOUT_OV_WARN_LIMIT command sets the value of the output voltage measured across RS_+ and RS_-,
RS_MAX16064
RS_+
R1 LOAD
R2
VO+ POWER SUPPLY
VO-
Figure 18. VOUT_SCALE_LOOP
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
VOUT_UV_FAULT_LIMIT (44h)
The VOUT_UV_FAULT_LIMIT command sets the value of the output voltage measured across RS_+ and RS_-, which causes an output undervoltage fault. This fault is masked until the output voltage reaches the programmed voltage at startup, and also during turn-off when the power supply is disabled. The 2 data bytes are in DIRECT format. Valid values are the same as VOUT_COMMAND. The default VOUT_UV_FAULT_LIMIT value is 00h. In response to violation of the VOUT_UV_FAULT_LIMIT, the MAX16064: 1) Sets the OTHER bit in the STATUS_BYTE. 2) Sets the OTHER bit in the STATUS_WORD. 3) Sets the VOUT bit in the STATUS_WORD. 4) Sets the VOUT Undervoltage Fault bit in the STATUS_VOUT register. 5) Sets the UV_FAULT bit in the STATUS_MFR_SPECIFIC register. 6) Sets the UV_FAULT bit in the MFR_STATUS_WORD register. 7) Sets the OTHER bit in the MFR_STATUS_WORD. 8) Responds as specified by VOUT_UV_FAULT_RESPONSE bits in the MFR_FAULT_RESPONSE register. 9) Notifies the host using SMBALERT assertion.
OT_WARN_LIMIT (51h)
The OT_WARN_LIMIT command sets the temperature, in degrees Celsius, of the on-chip temperature sensor at which an overtemperature warning is detected. The 2 data bytes are in DIRECT format. Valid values are the same as the OT_FAULT_LIMIT. The default OT_WARN_LIMIT value is 00h. In response to the OT_WARN_LIMIT being exceeded, the MAX16064: 1) Sets the TEMPERATURE bit in the STATUS_BYTE. 2) 3) 4) 5) 6) Sets the TEMPERATURE bit in the STATUS_WORD. Sets the TEMPERATURE bit in the MFR_STATUS_WORD. Sets the Overtemperature Warning bit in the STATUS_TEMPERATURE. Sets the OT_WARN bit in the MFR_STATUS_WORD register. Notifies the host through SMBALERT using assertion.
MAX16064
TON_DELAY (60h)
TON_DELAY sets the time, in milliseconds, from when a start condition is received (a valid OPERATION command or through A3/CONTROL when enabled) until the power-supply output voltage starts to rise. During TON_DELAY, the power supply is disabled (ENOUT_ deasserted) until TON_DELAY expires. Also, the undervoltage fault and warning are masked off during TON_DELAY. The 2 data bytes are in DIRECT format. Valid values are from 0 to 3276.7ms. The default TON_DELAY value is 0.
OT_FAULT_LIMIT (4Fh)
The OT_FAULT_LIMIT command sets the temperature, in degrees Celsius, of the on-chip temperature sensor at which an overtemperature fault is detected. The 2 data bytes are in DIRECT format. Valid values are from -142.5C to +395.4C. The default OT_FAULT_LIMIT value is 00h. In response to the OT_FAULT_LIMIT being exceeded, the MAX16064: 1) Sets the TEMPERATURE bit in the STATUS_BYTE. 2) Sets the TEMPERATURE bit in the STATUS_WORD. 3) Sets the TEMPERATURE bit in the MFR_STATUS_WORD. 4) Sets the Overtemperature Fault bit in the STATUS_TEMPERATURE. 5) Sets the OT_FAULT bit in the MFR_STATUS_WORD register. 6) Responds as specified by OT_FAULT_RESPONSE bits in the MFR_FAULT_RESPONSE register. 7) Notifies the host using SMBALERT assertion.
TON_RISE (61h)
The TON_RISE sets the time, in milliseconds, from when the power-supply output voltage starts to rise until the voltage has entered the regulation band. During TON_RISE, the voltage and temperature-related faults and warnings are masked off. Meanwhile, the MAX16064 still responds to the PMBus command. If a TON_RISE parameter results in the DAC outputting an out-of-range value (valid range 0 to 4090) immediately during TON_RISE, the CML flag is set and SMBALERT asserts to issue a warning.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
In feedback mode, the MAX16064 leaves the S_ switch on the DAC open during soft-start. It waits for the TON_RISE time to expire before adjusting the DAC output to equal the DACOUT_ feedback and then closes the S_ switch. The 2 data bytes are in DIRECT format. In REFIN mode, the TON_RISE parameter is a 16-bit value and the valid values are from 0.01ms to 32.767ms. In FB mode, the TON_RISE is a 14-bit value and the valid values are from 0.01ms to 16.383ms (the upper 2 bits are ignored). The default TON_RISE value is 0.01ms. Setting any value less than this minimum value defaults to 0.01ms. command can only be used with a device whose output can sink enough current to cause the output voltage to decrease at a controlled rate. When commanded to turn off immediately through the OPERATION command, the TOFF_FALL value is ignored. When commanded to turn off through the OPERATION soft-off command or A3/CONTROL (when enabled) or EN, the TOFF_FALL parameter is used. If a TOFF_FALL parameter results in the DAC outputting an out-of-range value (valid range 0 to 4090) immediately during TOFF_FALL, the CML flag is set and SMBALERT asserts to issue a warning. In feedback mode, this value is not used. The MAX16064 disables ENOUT_ and opens the DAC switch immediately after the TOFF_DELAY. The 2 data bytes are in DIRECT format. Valid values are from 0.01ms to 32.767ms. Do not set TOFF_FALL to any value less than 0.1ms.
TOFF_DELAY (64h)
The TOFF_DELAY sets the time, in milliseconds, from when a STOP condition is received (a soft-off OPERATION command or through A3/CONTROL when enabled) until the power supply stops transferring energy to the output. When commanded to turn off immediately through the OPERATION command, the TOFF_DELAY value is ignored. When commanded to turn off through A3/CONTROL (when enabled) or EN, the TOFF_DELAY parameter is used. The 2 data bytes are in DIRECT format. Valid values are from 0 to 3276.7ms. The default TOFF_DELAY value is 0.
STATUS_BYTE (78h)
The STATUS_BYTE command returns 1 byte of information with a summary of the most critical faults. A value of 1 indicates that a fault or warning event has occurred and a 0 indicates otherwise. Bits for unsupported features shall be reported as 0. The STATUS_BYTE cannot be restored by RESTORE_DEFAULT_ALL command. The STATUS_BYTE message content is described in Table 9. This command is read only. The default STATUS_BYTE value is 40h (power supply is off).
TOFF_FALL (65h)
The TOFF_FALL command sets the time, in milliseconds, from the end of the turn-off delay time until the output voltage is commanded to zero. Note that this
Table 9. STATUS_BYTE Message Contents
BIT NUMBER 7 6 5 4 3 2 1 0 STATUS BIT NAME BUSY OFF VOUT_OV IOUT_OC VIN_UV TEMPERATURE CML OTHER MEANING A fault was declared because the device was busy and unable to respond. (The BUSY bit is not supported. This bit always returns 0). This bit is asserted if ENOUT is presently disabling the power supply, regardless of the reason, including simply not being enabled. An output overvoltage fault has occurred. An output overcurrent fault has occurred. (The IOUT_OC bit is not supported. This bit always returns 0). An input undervoltage fault has occurred. (The VIN_UV bit is not supported. This bit always returns 0). A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. A fault or warning not listed in bits [7:1] has occurred. See the MFR_STATUS_WORD (D8h) section for more information.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
STATUS_WORD (79h)
The STATUS_WORD command returns two bytes of information with a summary of the reason for a fault. The low byte of the STATUS_WORD is the same data as the STATUS_BYTE. The STATUS_WORD message content is described in Table 10.
STATUS_VOUT (7Ah)
The STATUS_VOUT command returns one byte of information with contents as described in Table 11.
MAX16064
Table 10. STATUS_WORD Message Contents
BYTE BIT NUMBER 7 6 5 High 4 3 2 1 0 7 6 5 Low 4 3 2 1 0 STATUS BIT NAME VOUT IOUT/POUT INPUT MFR POWER_GOOD# FANS OTHER UNKNOWN BUSY OFF VOUT_OV IOUT_OC VIN_UV TEMPERATURE CML OTHER MEANING An output-voltage fault or warning has occurred. The IOUT/POUT bit is not supported. This bit always returns 0. The INPUT bit is not supported. This bit always returns 0. A manufacturer-specific fault or warning has occurred. The POWER_GOOD# bit is not supported. This bit always returns 0. The FANS bit is not supported. This bit always returns 0. Reserved. A fault type not given in bits [15:1] of the STATUS_WORD has been detected. A fault was declared because the device was busy and unable to respond. The BUSY bit is not supported. This bit always returns 0. This bit is asserted if ENOUT is presently disabling the power supply, regardless of the reason, including simply not being enabled. An output overvoltage fault has occurred. An output overcurrent fault has occurred. The IOUT_OC bit is not supported. This bit always returns 0. An input undervoltage fault has occurred. The VIN_UV bit is not supported. This bit always returns 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. A fault or warning not listed in bits [7:1] has occurred. See the MFR_STATUS_WORD (D8h) section for more information.
Table 11. STATUS_VOUT Message Contents
BIT NUMBER 7 6 5 4 3 2 1 0 VOUT overvoltage fault VOUT overvoltage warning VOUT undervoltage fault VOUT undervoltage warning VOUT_MAX warning This bit is not supported. This bit always returns 0. TON_MAX_FAULT This bit is not supported. This bit always returns 0. TOFF_MAX_WARNING This bit is not supported. This bit always returns 0. VOUT tracking error This bit is not supported. This bit always returns 0. MEANING
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
STATUS_TEMPERATURE (7Dh)
The STATUS_TEMPERATURE command returns one byte of information with contents as described in Table 12.
STATUS_MFR_SPECIFIC (80h)
The STATUS_MFR_SPECIFIC command returns one byte of information with a summary of the reason for a fault. The STATUS_MFR_SPECIFIC message content is described in Table 14.
STATUS_CML (7Eh)
The STATUS_CML command returns one byte of information with contents as described in Table 13.
Table 12. STATUS_TEMPERATURE Message Contents
BIT NUMBER 7 6 5 4 3 2 1 0 Overtemperature fault Overtemperature warning Undertemperature fault This bit is not supported. This bit always returns 0. Undertemperature warning This bit is not supported. This bit always returns 0. Reserved Reserved Reserved Reserved MEANING
Table 13. STATUS_CML Message Contents
BIT NUMBER 7 6 5 4 3 2 1 0 Invalid or unsupported data received Packet error check (PEC) failed Memory fault detected This bit is not supported. This bit always returns 0. Processor fault detected This bit is not supported. This bit always returns 0. Reserved A communication fault other than the ones listed in this table has occurred. This bit is not supported. This bit always returns 0. Other memory of logic fault has occurred. This bit is not supported. This bit always returns 0. MEANING Invalid or unsupported command received
Table 14. STATUS_MFR_SPECIFIC Message Contents
BIT NUMBER 7 6 5 4 3 2 1 0 STATUS BIT NAME EN_FAULT OT_WARN OT_FAULT ADCERR_FAULT N/A UV_WARN UV_FAULT OV_WARN MEANING EN input is below its threshold when OPERATION is on. Overtemperature warning (same as STATUS_TEMPERATURE bit 6). Overtemperature fault (same as STATUS_TEMPERATURE bit 7). An ADC conversion fault has occurred. This bit is reserved and always returns 0. A VOUT undervoltage warning has occurred (same as STATUS_VOUT bit 4). A VOUT undervoltage fault has occurred (same as STATUS_VOUT bit 5). A VOUT overvoltage warning has occurred (same as STATUS_VOUT bit 6).
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
READ_VOUT (8Bh)
The READ_VOUT command returns the actual measured (not commanded) output voltage across RS_+ and RS_-. If filter mode is enabled, the filtered value is returned. The 2 data bytes are in DIRECT format. Valid values are the same as VOUT_COMMAND. The default READ_VOUT value is 00h.
MFR_REVISION (9Bh)
The MFR_REVISION command reads the ASCII characters that contain the MAX16064 revision number with a block read command. The default MFR_REVISION value is 31h (1). This command is read only.
MAX16064
MFR_LOCATION (9Ch)
The MFR_LOCATION command loads the device with text (ISO/IEC 8859-1) characters that identify the facility that manufactures the power supply. The maximum number of characters is 20. This can be written to external EEPROM using the STORE_DEFAULT_ALL command. If an external EEPROM is not used, the command returns the text string MXIM.
READ_TEMPERATURE_1 (8Dh)
The MAX16064 supports only one temperature reading, READ_TEMPERATURE_1. The MAX16064 returns the actual on-chip measured temperature in degrees Celsius. The 2 data bytes are in DIRECT format. Valid values are the same as OT_FAULT_LIMIT. The default READ_TEMPERATURE_1 value is 00h.
MFR_DATE (9Dh)
The MFR_DATE command loads the device with text (ISO/IEC 8859-1) characters that identify the date of manufacture of the power supply. The maximum number of characters is 8. This can be written to external EEPROM using the STORE_DEFAULT_ALL command. If an external EEPROM is not used, the command returns the text string 080416.
PMBUS_REVISION (98h)
The PMBUS_REVISION command returns the revision of the PMBus specification to which the MAX16064 is compliant. The command has 1 data byte. Bits [7:5] indicate the revision of PMBus specification Part I to which the MAX16064 is compliant. Bits [4:0] indicate the revision of PMBus specification Part II to which the MAX16064 is compliant. The values are shown in Table 15. This command is read only. The PMBUS_REVISION value returned is 00h which indicates that the MAX16064 is compliant with Part I Rev 1.0 and Part II Rev 1.0.
MFR_SERIAL (9Eh)
The MFR_SERIAL command loads the device with text (ISO/IEC 8859-1) characters that uniquely identify the power supply. The maximum number of characters is 16. This can be written to external EEPROM using the STORE_DEFAULT_ALL command. If an external EEPROM is not used, the command returns the text string 00000000.
Table 15. PMBus Revision Data Byte Contents
BITS [7:5] 000 PART I REVISION 1.0 BITS [4:0] 00000 PART II REVISION 1.0
USER_DATA_00 (B0h)
The USER_DATA_00 command loads the device with user data. The maximum number of bytes is 40. This can be written to external EEPROM using the STORE_DEFAULT_ALL command. If an external EEPROM is not used, the command returns 00h for all bytes.
MFR_ID (99h)
The MFR_ID command returns the MAX16064 manufacturer's identification. The default MFR_ID value is 4Dh (M). This command is read only.
MFR_SMB_LOOPBACK (D0h)
The MFR_SMB_LOOPBACK command returns the data word previously received by the MAX16064. The SMBus master writes a data word to the MAX16064 using this command and then retrieves the data word. A valid communication channel is established if the master reads back the same word. Note that if another command is sent in between the write MFR_SMB_LOOPBACK command and the read MFR_SMB_LOOPBACK command, the MAX16064 returns whatever last command data word it receives.
MFR_MODEL (9Ah)
The MFR_MODEL command returns the MAX16064 model number. The default MFR_MODEL value is 43h (C). This command is read only.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
MFR_MODE (D1h)
The MFR_MODE command is used to configure the MAX16064 to support manufacturer specific commands. The MFR_MODE command is described in Table 16. The default MFR_MODE value is 00h.
Table 16. MFR_MODE Bit Definition
BIT BIT NAME DESCRIPTION This is equivalent to the number of external clock cycles provided to CLKIO in 100_S - 2. MFR_MODE[15:8] = fEXT_CLK/10kHz - 2 where fEXT_CLK is the frequency of the external clock. For example, when fEXT_CLK = 1MHz, fEXT_CLK/10kHz = 100, MFR_MODE[15:8] = 100 - 2 = 98. Valid Input Clock Time external input clock range is from 100kHz (MFR_MODE[15:8] = 8) to 2.5MHz (MFR_MODE[15:8] = 248). Factor These bits are ignored if internal clock source is selected as the time base (Clock Source Select bit = 0). The Clock Out Enable bit allows the output of a 1MHz reference clock to CLKIO for synchronizing multiple MAX16064s. 1 = Enables the 1MHz output on CLKIO. 0 = Reference clock is not output (default). 1 = The EN state is ignored and the MAX16064 is controlled according to ON_OFF_CONFIG. 0 = The MAX16064 turns on the external power supplies when EN exceeds its threshold. If EN goes low after power-up, the MAX16064 turns off a power supply only if MFR_FAULT_RESPONSE[5:4] is configured to do so. The EEPROM Lock Enable bit is used to protect external EEPROM data from being overwritten. 1 = The STORE_DEFAULT_ALL command is ignored. The RESTORE_DEFAULT_ALL command is still valid. 0 = The STORE_DEFAULT_ALL command initiates a store configuration operation to the external EEPROM attached to A1/SCLE and A2/SDAE (default). Correction Bypass Enable. 1 = Disables a correction algorithm made to voltage and temperature readings. 0 = Applies a correction algorithm to temperature measurement, thus resulting in high-accuracy readings. For optimal operation, this bit should be cleared to 0 (default). 1 = EEPROM fault locations are locked. If a fault occurs, data is not written to the external EEPROM. 0 = EEPROM fault locations are unlocked. If a fault occurs, data is written to the external EEPROM. 1 = PEC enabled for all commands. 0 = PEC is disabled (default). 1 = Disable filtering of the voltage and temperature conversions. 0 = Enable filtering of the voltage and temperature conversions (default). The Clock Source Select bit determines the MAX16064 reference clock time source. 1 = An external clock must be supplied to CLKIO and is used as the MAX16064 reference clock. 0 = The internal clock is used.
15:8
7
Clock Out Enable
6
IGNORE_EN
5
EEPROM Lock Enable
4
Correction Bypass Enable
3 2 1
EEPROM Fault Lock PEC Enable Filter Setting Clock Source Select
0
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
MFR_SAMPLE_RATE (D3h)
The MFR_SAMPLE_RATE command sets the frequency (Hz) at which the ADC conversion result registers (representing four voltages and one temperature) are compared with their threshold limits. This parameter does not control the total ADC sampling rate, which is controlled by MFR_VLTO. Also, the output-voltage adjustment rate is not affected by this parameter. Monitor Sample Frequency = 10kHz/MFR_SAMPLE_RATE The 2 data bytes are formatted as positive integers. Valid values are from 1 to 65535. Do not set this value to 0. The default MFR_SAMPLE_RATE value is 50 which is equivalent to a sample frequency of 200Hz. The default MFR_VOUT_PEAK value is 0.
MAX16064
MFR_TEMPERATURE_PEAK (D6h)
The MFR_TEMPERATURE_PEAK command returns the maximum actual on-chip measured temperature in degrees Celsius. To reset this value to its lowest value, write to this command with a data value of 0FFFFh. Any other values written by this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. Valid values are the same as OT_FAULT_LIMIT. The default MFR_TEMPERATURE_PEAK value is 00h.
MFR_STATUS_WORD (D8h)
When a warning or fault condition is detected, the MAX16064 sets the corresponding bit in the MFR_STATUS_WORD register to 1 and notifies the host using SMBALERT assertion. The MFR_STATUS_WORD [7:0] (low byte) bits are the same definition and state as the STATUS_BYTE command. This register is cleared to 0 together with the STATUS_BYTE register by any of the fault/warning clearing methods mentioned earlier in the CLEAR_FAULTS command. The MFR_STATUS_WORD command value cannot be restored by the RESTORE_DEFAULT_ALL command. This command is read only.
MFR_VOUT_PEAK (D4h)
The MFR_VOUT_PEAK command returns the maximum actual measured (not commanded) output voltage in volts across RS_+ and RS_-. If the filter mode is enabled, instead of returning the instantaneous value, the filtered output voltage is returned. To reset this value to 0, write to this command with a data value of 0. Any other values written by this command are used as a comparison for future peak updates. The 2 data bytes are in DIRECT format. Valid values are the same as VOUT_COMMAND.
Table 17. MFR_STATUS_WORD Bit Definition
BIT NUMBER 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 STATUS BIT NAME EN_FAULT OT_WARN OT_FAULT ADCERR_FAULT N/A UV_WARN UV_FAULT OV_WARN BUSY OFF VOUT_OV IOUT_OC VIN_UV TEMPERATURE CML OTHER MEANING EN input is below its threshold when OPERATION is on. Overtemperature warning (Same as STATUS_TEMPERATURE bit 6). Overtemperature fault (Same as STATUS_TEMPERATURE bit 7). An ADC conversion fault has occurred. This bit is reserved and always returns 0. A VOUT undervoltage warning has occurred (same as STATUS_VOUT bit 4). A VOUT undervoltage fault has occurred (same as STATUS_VOUT bit 5). A VOUT overvoltage warning has occurred (same as STATUS_VOUT bit 6). A fault was declared because the device was busy and unable to respond. The BUSY bit is not supported. This bit always returns 0. This bit is asserted if ENOUT is presently disabling the power supply, regardless of the reason, including simply not being enabled. An output overvoltage fault has occurred. An output overcurrent fault has occurred. The IOUT_OC bit is not supported. This bit always returns 0. An input undervoltage fault has occurred. The VIN_UV bit is not supported. This bit always returns 0. A temperature fault or warning has occurred. A communication, memory, or logic fault has occurred. A fault or warning not listed in bits [7:1] has occurred.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
MFR_FAULT_RESPONSE (D9h)
The MFR_FAULT_RESPONSE command specifies the response to each fault condition supported by the MAX16064. Each fault has 2 response bits that describe how the MAX16064 responds to that particular fault. It is also used to record the condition under which a fault occurs. The STORE_PEAK function is used to store peak values (MFR_VOUT_PEAK and MFR_TEMPERATURE_PEAK) to the EEPROM (if present) on a fault detection regardless of the status of the EEPROM Lock Enable bit. Setting the STORE_PEAK bit to 1 enables the store function.
MFR_FAULT_RETRY (DAh)
The MFR_FAULT_RETRY command sets the time between restarting the power supply if the fault response is to restart the power supply at specified intervals. This command sets the retry time delay in multiples of 100s. This command value is used for all fault responses that require delay retry. Delay Retry Time = MFR_FAULT_RETRY [15:0] x 100s The 2 data bytes are in DIRECT format. Valid values are from 0 to 3.2768s. When MFR_FAULT_RETRY = 00h, the MAX16064 restarts the power supply at the next available time period. The default MFR_FAULT_RETRY value is 00h.
Table 18. MFR_FAULT_RESPONSE Bit Definition
BITS 15 14 13:8 7:6 5:4 3:2 1:0 FAULT RESPONSE BIT NAME 1 = Save fault data to EEPROM. 0 = Do not save fault data to EEPROM. 1 = Lock EEPROM to further fault status writes after saving state (see bit 15). 0 = Do not lock the EEPROM to further fault status writes. Reserved OT_FAULT_RESPONSE[1:0] EN_FAULT_RESPONSE[1:0] VOUT_UV_FAULT_LIMIT_RESPONSE[1:0] VOUT_OV_FAULT_LIMIT_RESPONSE[1:0]
Table 19. Fault Response Options
RESPONSE[1:0] 11 FAULT RESPONSE OPTION Set the corresponding fault bit in the fault status register, assert SMBALERT, save fault state to EEPROM (if enabled by bit 15) and continue operation. Set the corresponding fault bit in the fault status register, assert SMBALERT, shut down the power supply (deassert ENOUT) and restart the power supply every T (s), where T is set in the MFR_FAULT_RETRY register. Set the corresponding fault bit in the fault status register, assert SMBALERT and shutdown the power supply. Store fault data to EEPROM if enabled by bit 15. Set the corresponding fault bit in the fault status register, assert SMBALERT and continue operation without any action.
10
01 00
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
MFR_SET_ADDRESS (DBh)
The MFR_SET_ADDRESS command is used to change the MAX16064 slave address. By default the MAX16064 address is set by A3:A1 upon reset according to Table 3. After reset, the slave address can be changed by the MFR_SET_ADDRESS command. See the MAX16064 Address Assignment section. This command has 2 data bytes. The slave address is contained in bits [6:0] of the first data byte. Bit 7 of the first data byte must be 0. tRP = (MFR_RESET_DELAY) x [MFR_SAMPLE_RATE x (100 x 10-6)] For example, if MFR_RESET_DELAY = 20 and MFR_SAMPLE_RATE = 50, then the minimum reset timeout period is t RP = (20) x [50 x (100 x 10 -6)] = 100ms. Note that the resolution of tRP is MFR_SAMPLE_RATE x 100s, so in this example is 50 x 100s = 5ms. The 2 data bytes are in DIRECT format. Valid values are from 0 to 3276.7ms. The default MFR_RESET_DELAY value is 0ms.
MAX16064
MFR_RESET_DELAY (DDh)
MFR_RESET_DELAY sets the reset timeout, tRP, from when the associated power-supply output voltage reaches regulation and the RESET output deasserts (see Figure 9). The reset timeout is also dependent upon MFR_SAMPLE_RATE. The minimum tRP is calculated as follows:
MFR_MODE_OUTPUT (DEh)
The MFR_MODE_OUTPUT command is described in Table 20.
Table 20. MFR_MODE_OUTPUT Bit Definition
BIT 5 4 BIT NAME DAC Switch Mode Global Fault Select DESCRIPTION 1 = DAC switch is open when REFIN mode power supply is turned off. 0 = DAC switch remains closed when REFIN mode power supply is turned off. 1 = Faults on this output causes faults on other outputs as well. 0 = Faults on this output only affects this output (default). The Input Range Select bit determined the full-scale range of the RS+/RS- voltage conversion. 1 = 5.5V. 0 = 2.0V (default). Prior to sending any voltage-related commands, the user application must first configure the desired input range. All voltage-related commands use the specified input range to convert the commanded value to internal register values. Changing the Input Range Select bit while the power supply is on is not recommended. This may result in unpredictable and possible catastrophic operation since all voltage-related commands continue to refer to the input range that was in effect when the command was received. ENOUT Polarity Select The ENOUT Polarity bit selects the ENOUT active-on polarity. See the ENOUT_ Operation section. 1 = ENOUT asserted on-state is the same as the default startup state (low). 0 = ENOUT asserted on-state is the inverse of the default startup state (high). The Feedback Mode Select bit selects the closed-loop voltage control operation mode. 1 = Feedback mode. 0 = Refin mode (default). 1 = Writes when PAGE = 255 does not affect this output. 0 = Writes when PAGE = 255 affects this output (default).
3
Input Range Select
2
1
Feedback Mode Select Page 255 Control
0
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
MFR_VLTO (DFh)
The Voltage Loop Timeout command sets the time between each of the five ADC conversions. The time (VLTO) is calculated as VLTO = N x 250ns, where N is the 16-bit data included in the command. The range of values is 0 to 16.38ms. The default value at power-up is 100, or 25s. The total ADC acquisition time is: (1.75s + 0.25s x MFR_VLTO)+ 4 x (4 x 1.75s + 0.25s x MFR_VLTO) (filtering on) (1.75s + 0.25s x MFR_VLTO)+ 4 x (1.75s + 0.25s x MFR_VLTO) (filtering off) where 1.75s represents a single ADC conversion time and MFR_VLTO is the value contained in the register. The internal ADC conversion registers are updated at this rate. However, the voltages and temperatures are monitored at another rate that is controlled by MFR_SAMPLE_RATE.
fAVOC = 1 MFR _ DAC _ ACT _ CNT x (8.75 x 10-6 + 1.25 x 10-6 x MFR _ VLTO)
MFR_RESET_OUTPUT (E1h)
RESET is an active-low open-drain output that is low when the device is powering on. RESET is assigned to one of the power supplies using the MFR_RESET_OUTPUT command. When that power-supply output is at the target voltage, RESET goes high after the reset timeout period (see Figure 9). The reset timeout period is set by the MFR_RESET_DELAY command. The MFR_RESET_OUTPUT value defines which powersupply output affects RESET. If MFR_RESET_OUTPUT is set to 0, 1, 2, or 3, then RESET goes high MFR_RESET_DELAY after that output has reached its target value. If MFR_RESET_OUTPUT is any other value, RESET is permanently low. If the power-supply output selected by MFR_RESET_OUTPUT is later disabled for any reason (either due to a fault condition, or an OPERATION OFF command), then RESET goes low. To enable faults on any power supply to cause RESET to go low, set the MFR_MODE_OUTPUT.GLOBALFAULTS bit to a 1 for all the supplies.
MFR_DAC_ACT_CNT (E0h)
The MFR_DAC_ACT_CNT command sets the number of ADC samples taken before updating the DAC output voltage during AVOC mode. The resulting adjustment rate is:
fAVOC = 1 MFR _ DAC _ ACT _ CNT x (29.75 x 10-6 + 1.25 x 10-6 x MFR _ VLTO)
MFR_FAULT_REASON (E2h)
The MFR_FAULT_REASON command returns the results of the voltage threshold comparisons for all channels following a fault condition.
where fAVOC is the update period, in Hertz. This formula applies only when input filtering is turned on (MFR_MODE[1] = 0). When the filter is turned off, the following formula applies:
Table 21. MFR_FAULT_REASON Bit Definition
BIT 15 14 13 12 11 BIT NAME Reserved Reserved VFMIN3 VFMAX3 Reserved Reserved Reserved 1 = Voltage at RS3 is less than the VOUT_UV_FAULT_LIMIT. 0 = Voltage at RS3 greater than or equal to VOUT_UV_FAULT_LIMIT. 1 = Voltage at RS3 is greater than the VOUT_OV_FAULT_LIMIT. 0 = Voltage at RS3 less than or equal to VOUT_OV_FAULT_LIMIT. Reserved DESCRIPTION
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Table 21. MFR_FAULT_REASON Bit Definition (continued)
BIT 10 9 8 7 6 5 4 3 2 1 0 BIT NAME Reserved VFMIN2 VFMAX2 Reserved Reserved VFMIN1 VFMAX1 Reserved Reserved VFMIN0 VFMAX0 Reserved 1 = Voltage at RS2 is less than the VOUT_UV_FAULT_LIMIT. 0 = Voltage at RS2 greater than or equal to VOUT_UV_FAULT_LIMIT. 1 = Voltage at RS2 is greater than the VOUT_OV_FAULT_LIMIT. 0 = Voltage at RS2 less than or equal to VOUT_OV_FAULT_LIMIT. Reserved Reserved 1 = Voltage at RS1 is less than the VOUT_UV_FAULT_LIMIT. 0 = Voltage at RS1 greater than or equal to VOUT_UV_FAULT_LIMIT. 1 = Voltage at RS1 is greater than the VOUT_OV_FAULT_LIMIT. 0 = Voltage at RS1 less than or equal to VOUT_OV_FAULT_LIMIT. Reserved Reserved 1 = Voltage at RS0 is less than the VOUT_UV_FAULT_LIMIT. 0 = Voltage at RS0 greater than or equal to VOUT_UV_FAULT_LIMIT. 1 = Voltage at RS0 is greater than the VOUT_OV_FAULT_LIMIT. 0 = Voltage at RS0 less than or equal to VOUT_OV_FAULT_LIMIT. DESCRIPTION
MFR_FAULT_VOUT (E3h)
The MFR_FAULT_VOUT command returns VOUT at the time a voltage fault was triggered.
System designers are thus urged to derive optimum configuration based on the particular system needs.
Graphic User Interface (GUI)
The MAX16064 Evaluation Kit comes with a free GUI that eliminates the need for any software development and provides a simple and user-friendly method for configuring large systems in a short time. Once the configuration is complete, the results can be saved to the external EEPROM for MAX16064 configuration on power-up, or loaded at power-up onto the MAX16064 through the PMBus by a master controller. The powerful MAX16064 feature set can be inferred from the GUI screenshot shown in Figure 19, where the programmable parameters are displayed. These parameter values set serve as data bytes for PMBus and manufacturerspecific commands supported by the MAX16064. For details on using the GUI, refer to the MAX16064 Evaluation Kit.
MFR_FAULT_TEMP (E4h)
The MFR_FAULT_TEMP command returns the temperature at the time a temperature fault was triggered.
Applications Information
Performance Consideration
The MAX16064 can be viewed as a task scheduler where it periodically goes through its task list and performs the required tasks. While it may be tempting to monitor the power supplies at the highest supported frequency, MFR_SAMPLE_RATE, it must be noted that doing so takes away resources from other tasks, such as communication with the system controller. Since each application is unique in its own merit, it is impossible to prescribe a solution that suffices in all conditions.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Figure 19. MAX16064 Graphic User Interface
PCB Consideration
Accurate voltage measurement and voltage regulation can be achieved by following these guidelines for good PCB layout: 1) Place IC decoupling and filter capacitors for AVDD, DVDD, REFO, and RS_C as close as possible to the IC pins. If using an external EEPROM, place it close to the MAX16064 and use short direct traces for interconnections. 2) Use Kelvin connections for the differential pair traces from the desired remote-sense points on the power-supply output-voltage power plane to RS_+ and RS_- of the MAX16064 for accurate powersupply output-voltage sensing.
3)
4)
Connect the analog grounds (AGND, AGND1) and digital ground (DGND) of the MAX16064 to a ground plane right at the IC. Terminate all other ground connections to this ground plane. Connect this ground plane to the quiet analog ground plane of the power supply so that the reference voltage to the power supply is unaffected by switching noise. Use a single-point (star) grounding technique to connect the analog ground plane of the power supply to the heat dissipating power ground plane of the power supply. Place MAX16064 as close as possible to the power supply for best temperature measurement performance. Refer to the MAX16064 Evaluation kit for a sample layout.
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface
Typical Operating Circuit
12V BUS
MAX16064
N DC-DC REFIN EN LOAD OUT IN LDO EN FB OUT
OUT
LOAD
N DC-DC REFIN EN OUT OUT IN LDO EN LOAD LOAD FB OUT
DACOUT1
DACOUT2
ENOUT1
ENOUT2
RS1C
RS1+
RS1-
RS2C
RS2+
RS0RS0+ RS0C
RS2-
ENOUT3
DACOUT3 RS3+ RS3-
ENOUT0 DACOUT0
RS3C
MAX16064
3.3V
EN A3/CONTROL DGND DVDD AGND AVDD RSVD REFO CLKIO A2/SDAE A1/SCLE AGND1
RESET SMBALERT SDA SCL SYSTEM CONTROLLER
3.3V
EEPROM
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0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface MAX16064
Pin Configuration
TOP VIEW DACOUT2 DACOUT3 RSVD DVDD DGND SDA SCL
24 23 22 21 20 19
27
26
25
AVDD AGND1
RS1RS1+ RS1C REFO RS0+ RS0C RS0DACOUT0 RS2C
28 29 30 31 32 33 34 35 36
18 17 16 15 14 13 12 11 10 2 3 4 5 6 7 8 9
SMBALERT RESET A3/CONTROL A2/SDAE A1/SCLE CLKIO ENOUT3 ENOUT2 ENOUT1
MAX16064
*EP
+
1
RS2RS2+
RS3+ RS3RS3C EN
THIN QFN
*EP = EXPOSED PAD.
Chip Information
PROCESS: BiCMOS
DACOUT1 AGND ENOUT0
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE 36 TQFN-EP PACKAGE CODE T3666-3 DOCUMENT NO. 21-0141
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
52 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.

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