 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 D D D D D D D D Fast Transient Response 10-mA to 5-A Load Current Short Circuit Protection Maximum Dropout of 500-mV at 5-A Load Current Separate Bias (VB) and VIN Pins Available in Adjustable or Fixed Output Voltages 5-Pin Package Allows Kelvin Sensing of Load Voltage Reverse Current Protection 5-PIN TO-220 T PACKAGE (TOP VIEW) 5-PIN TO-263 TD PACKAGE (TOP VIEW) Note: Tab = Ground description The UC385 is a low dropout linear regulator providing a quick response to fast load changes. Combined with its precision on-board reference, the UC385 excels at driving GTL and BTL buses. Due to its fast response to load transients, the total capacitance required to decouple the regulator's output can be significantly decreased when compared to standard LDO linear regulators. Dropout voltage (VIN to VOUT) is only 490 mV maximum and 350 mV typical at 5-A load (0C to 100C). The on-board bandgap reference is stable with temperature and scaled for a 1.2 V input to the internal power amplifier. The UC385 is available in fixed output voltages of 1.5 V, 2.1 V, or 2.5 V. The output voltage of the adjustable version can be set with two external resistors. If the external resistors are omitted, the output voltage defaults to 1.2 V. block diagram VB 1 R1 UC382-ADJ UC382-1 (1.5 V) UC382-2 (2.1 V) UC382-3 (2.5 V) THERMAL SHUTDOWN 2 1.2 V BANDGAP REFERENCE + VIN OPEN 2 k 2 k 2 k R2 0 500 1.5 k 2.16 k R1 R2 SHORT CIRCUIT SENSE 3 GND 5 ADJ 4 VOUT UDG-00084 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright (c) 2000, Texas Instruments Incorporated POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 1 SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR absolute maximum ratings over operating free-air temperature (unless otherwise noted) VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 V Output Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 V to -6.0 V Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -65C to 150C Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55C to 150C Lead Temperature (Soldering, 10 seconds) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300C 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 under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. AVAILABLE OPTIONS PACKAGED DEVICES TO-220 (T) TJ 1.5 V -40C to 100C 0C to 100C 285T-1 385T-1 OUTPUT VOLTAGE 2.1 V 285T-2 385T-2 2.5 V 285T-3 385T-3 1.2 V or ADJ 285T-ADJ 385T-ADJ 1.5 V 285TD-1 385TD-1 TO-263 (TD) OUTPUT VOLTAGE 2.1 V 285TD-2 385TD-2 2.5 V 285TD-3 385TD-3 1.2 V or ADJ 285TD-ADJ 385TD-ADJ electrical characteristics unless otherwise stated, these parameters apply for TA = -40 C to 100 C for the UC285-x series and 0 C to 100 C for the UC385-x, VB = 5 V; VIN = 3.3 V, VOUT = 2.5 V, TA = TJ. PARAMETER UC385-3 Fixed 2.5 V, 5-A Family Ou u o age Output voltage Load regulation VIN PSRR VB PSRR VIN d o ou voltage ( dropout o age (VIN - VOUT) OU ) UC385-3 UC285-3 VB dropout (VB - VOUT) d o ou ( OU ) Short circuit current limit VB cu e current VIN current UC385-2 Fixed 2.1 V, 5-A Family Output voltage Ou u o age Load regulation VIN PSRR VB PSRR UC385-2 UC285-2 IVOUT = 100 mA IVOUT = 100 mA IVOUT = 10 mA to 5 A 80 50 2.079 2.058 2.1 2.1 0.5 110 67 2.121 2.121 4 V V mV dB dB IVOUT = 10 mA IVOUT = 5 A IVOUT = 5 A 4.9 UC385-3 UC285-3 IVOUT = 5 A, IVOUT = 5 A IVOUT = 5 A IVOUT = 5 A IVOUT = 5 A 5.1 8 40 4.96 TJ = 25C UC385-3 UC285-3 IVOUT = 100 mA IVOUT = 100 mA IVOUT = 10 mA to 5 A 80 50 2.475 2.45 2.5 2.5 0.5 110 65 350 350 350 1.8 1.8 425 490 500 2.1 2.2 7.5 15 100 2.525 2.525 4 V V mV dB dB mV mV mV V V A mA mA A TEST CONDITION MIN TYP MAX UNIT 2 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 electrical characteristics unless otherwise stated, these parameters apply for TA = -40 C to 100 C for the UC285-x series and 0 C to 100 C for the UC385-x, VB = 5 V; VIN = 3.3 V, VOUT = 2.5 V, TA = TJ. PARAMETER UC385-2 Fixed 2.1 V, 5-A Family (continued) VIN d o ou voltage ( dropout o age (VIN - VOUT) OU ) UC385-2 UC285-2 VB dropout (VB - VOUT) d o ou ( OU ) Short circuit current limit VB cu e current VIN current UC385-1 Fixed 1.5 V, 5-A Family Output voltage Ou u o age Load regulation VIN PSRR VB PSRR VIN d o ou voltage ( dropout o age (VIN - VOUT) OU ) UC285-1 UC285-2 VB dropout (VB - VOUT) d o ou ( OU ) Short circuit current limit VB cu e current VIN = current UC385-ADJ Adjustable, 5-A Family ADJ voltage J o age Load regulation VIN PSRR VB PSRR VOUT VIN d o ou voltage ( dropout o age (VIN - VOUT) OU ) UC385-ADJ UC285-ADJ VB dropout (VB - VOUT) d o ou ( OU ) Short circuit current limit VB cu e current VIN current IVOUT = 10 mA IVOUT = 5 A IVOUT = 5 A 4.9 UC385-ADJ UC285-ADJ UC385-ADJ UC285-ADJ IVOUT - 100 mA IVOUT - 100 mA IVOUT = 10 mA to 5 A VOUT programmed for 2.5 V Programmed for 2.5 V IVOUT = 5 A, IVOUT = 5 A IVOUT = 5 A IVOUT = 5 A IVOUT = 5 A 5.1 8 40 4.96 TJ = 25C 1.188 1.176 80 50 1.2 1.2 0.5 110 65 350 350 350 1.8 1.8 425 490 500 2.1 2.2 7.5 15 100 1.212 1.212 4 V V mV dB dB mV mV mV V V A mA mA A IVOUT = 10 mA IVOUT = 5 A IVOUT = 5 A 4.9 UC385-1 UC285-1 IVOUT = 5 A, IVOUT 5 A IVOUT = 5 A IVOUT = 5 A IVOUT = 5 A 5.1 8 40 4.96 TJ = 25C UC385-1 UC285-1 IVOUT = 100 mA IVOUT = 100 mA IVOUT = 10 mA to 5 A 80 50 1.485 1.470 1.5 1.5 0.5 110 65 350 350 350 1.8 1.8 425 490 500 2.1 2.2 7.5 15 100 1.515 1.515 4 V V mV dB dB mV mV mV V V A mA mA A IVOUT = 10 mA IVOUT = 5 A IVOUT = 5 A 4.9 UC385-2 UC285-2 IVOUT = 5 A, IVOUT = 5 A IVOUT = 5 A IVOUT = 5 A IVOUT = 5 A 5.1 8 40 4.96 TJ = 25C 350 350 350 1.8 1.8 425 490 500 2.1 2.2 7.5 15 100 mV mV mV V V A mA mA A TEST CONDITION MIN TYP MAX UNIT POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 3 SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR pin descriptions ADJ: In the adjustable version, the user programs the output voltage with two external resistors. The resistors should be 0.1% for high accuracy. The output amplifier is configured as a non-inverting operational amplifier. The resistors should meet the criteria of R3 || R4 < 100 . Connect ADJ to VOUT for an output voltage of 1.2 V. Note that the point at which the feedback network is connected to the output is the Kelvin sense point. GND: For accurate results, the GND pin should be referenced to the load ground. VB: Supplies power to all circuits of the regulator except the output power transistor. The 2-V headroom from VB to VOUT allows the use of a Darlington output stage for inherently low output impedance and fast response. (Dropout is derated for junction temperatures below 0C.) VIN: Supplies the current to the collector of the output power transistor only. The dropout (VIN-VOUT) is under 100 mV for light loads; maximum dropout is 490 mV at 5 A for TJ = 0C to 100C. (Dropout is derated for junction temperatures over 100C.) VOUT: This pin should be connected to the load via a low impedance path. Avoid connectors which add significant inductance and resistance. Note that even though a Kelvin sense is available through a 5-pin package, care must be taken since voltage drops along wire traces add to the dropout voltage. DROPOUT VOLTAGE vs. LOAD CURRENT 1.7 TJ = 27 C 400 TJ = 27 C VDO - Dropout Voltage - V DROPOUT VOLTAGE vs. LOAD CURRENT VDO - Dropout Voltage - V 1.675 300 1.65 200 1.625 1.6 0 1 2 3 4 5 100 100m IL- Load Current - A 5 IL- Load Current - A Figure 1 Figure 2 4 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 APPLICATION INFORMATION The UC385 is easy to use. The adjustable version requires two resistors to set the output voltage. The fixed versions of the UC385 require no external resistors. All versions of the UC385 require decoupling capacitors on the input and output. In a typical application, VB and VIN are driven from switching power supplies which may have large filter capacitors at their outputs. If the UC385 is further than 12 inches from the power supply, it is recommended to add local decoupling as close as possible to the linear regulator. Decouple the output of the UC385 with at least 100 F of high quality tantalum or Sanyo OSCON capacitors close to the VOUT pin for maximum stability. Many applications involving ultra fast GTL or BTL applications require additional capacitance close to the load. The exact amount will vary according to speed and magnitude of the load transients and the tolerance allowed for transients on VOUT. When specifying the decoupling capacitors, the series resistance of the capacitor bank is an important factor in its ability to filter load transients. The UC385 allows for Kelvin sensing the voltage at the load. This improves regulation performance and eliminates the voltage drops due to wire trace resistance. This voltage drop must be added to the headroom (VIN to VOUT and VB to VOUT). The dropout of 350 mV is measured at the pins and does not include additional drops due to trace resistance. OPEN LOOP PHASE vs. FREQUENCY 0 70 60 CO = 100 mF IL = 1 A 50 40 30 20 10 0 -180 100 1k 10 k 100 k 1M OPEN LOOP GAIN vs. FREQUENCY CO = 100 mF IL = 1 A Phase - deg -90 Gain - dB -10 10 M 100 1k 10 k 100 k 1M 10 M f - Frequency - Hz f - Frequency - Hz Figure 3 Figure 4 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 5 SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR APPLICATION INFORMATION POWER SUPPLY REJECTION RATIO vs. FREQUENCY 60 PSSR - Power Supply Rejection Ratio - dB 50 40 30 20 10 0 100 1k 10 k 100 k 1M 10 M f - Frequency - Hz Figure 5 5V 1 F Ceramic 1 2 + 3.3 V 4.7 F Tantalum VIN VB VOUT 4 VO = 1.2 V + ADJ 5 100 F Tantalum 121 R1 IRF 520 Pulse Generator UC385-ADJ GND 3 UDG-00085 Figure 6. Transient Test Circuit 6 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 APPLICATION INFORMATION 10 mA to 3 A/ s Load Transient Response Figure 7 +5 V + 4.7 F Kelvin Sense Point VOUT 4 R3 60 ADJ 5 R4 120 + 330 F OSCON +1.0 V Output 1 +3.3 V + 4.7 F 2 VIN VB UC385-ADJ GND 3 2.2 F Ceramic UDG-00086 Figure 8. Typical UC385-ADJ Application POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 7 SLUS212C - NOVEMBER 1999 - REVISED MARCH 2000 UC285 1, UC285 2, UC285 3, UC285 ADJ, UC385 1, UC385 2, UC385 3, UC385 ADJ FAST TRANSIENT RESPONSE 5 A LOW DROPOUT REGULATOR APPLICATION INFORMATION +5 V + 4.7 F 2 VIN Kelvin Sense Point VOUT 4 + ADJ 5 330 F OSCON +1.5 V Output 2.2 F Ceramic 1 VB UC385-1 GND 3 UDG-00087 Figure 9. Typical UC385-1, -2, or -3 Application 8 POST OFFICE BOX 655303 * DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgment, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. Customers are responsible for their applications using TI components. In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI's publication of information regarding any third party's products or services does not constitute TI's approval, warranty or endorsement thereof. Copyright (c) 2000, Texas Instruments Incorporated |
Price & Availability of SLUS212C
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |