general description the MAX8875 low-dropout linear regulator operates from a +2.5v to +6.5v input range and delivers up to 150ma. a p-channel mosfet pass transistor allows its 85? sup- ply current to remain independent of the load, making this device ideal for battery-operated portable equipment such as pcs phones, cellular phones, cordless phones, and modems. the MAX8875 features a power-ok (pok) output that indi- cates when the output is out of regulation. the device is available in several preset output voltage versions: 5.0v, 3.3v, 3.0v, 2.7v, 2.5v, or 1.5v. other features include 1? (max) shutdown current, short-circuit protection, thermal shutdown protection, and reverse-battery protection. the device comes in a miniature 5-pin sot23 package. the MAX8875 is optimized for use with a 1? ceramic out- put capacitor. for a pin-compatible, functionally equivalent device for use with a higher esr output capacitor, see the max8885 data sheet. applications pcs telephones hand-held instruments cellular telephones palmtop computers cordless telephones electronic planners pcmcia cards modems features power-ok output small output capacitor (1f ceramic) preset output voltages (1% accuracy) guaranteed 150ma output current 85a no-load supply current low 110mv dropout at 100ma load (165mv at 150ma load) thermal-overload and short-circuit protection reverse-battery protection 60db psrr at 100hz 1a max shutdown current MAX8875 150ma, low-dropout linear regulator with power-ok output ________________________________________________________________ maxim integrated products 1 gnd pok shdn 1 5 out in MAX8875 sot23-5 top view 2 3 4 MAX8875 input +2.5v to +6.5v in out shdn gnd output preset 1.5v to 5.0v 150ma pok c out 1 f 100k c in 1 f to c off on typical operating circuit 19-1556; rev 1; 12/00 * xy is the output voltage code (see output voltage selector guide). note : other output voltages between 1.5v and 5.0v are avail- able in 100mv increments?ontact the factory for information. minimum order quantity is 25,000 units. pin configuration ordering information output voltage selector guide 5 sot23-5 pin-package temp. range -40? to +85? MAX8875eukxy-t part * top mark adqi adla adlb adlc adld 5.0 3.3 3.0 2.7 1.5 v out (v) part MAX8875euk15-t MAX8875euk27-t MAX8875euk30-t MAX8875euk33-t MAX8875euk50-t adkz 2.5 MAX8875euk25-t for price, delivery, and to place orders, please contact maxim distribution at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com.
MAX8875 150ma, low-dropout linear regulator with power-ok output 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v in = v out(nominal) + 1v, shdn = in, t a = -40? to +85?, unless otherwise noted. typical values are at t a = +25?.) (note 1) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. in, shdn , pok to gnd...............................................-7v to +7v shdn to in ...............................................................-7v to +0.3v out to gnd ................................................-0.3v to (v in + 0.3v) output short-circuit duration ........................................indefinite continuous power dissipation (t a = +70?) 5-pin sot23 (derate 7.1mw/? above +70?)..........571mw operating temperature range ...........................-40? to +85? junction temperature ......................................................+150? ja ...............................................................................+140?/w storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? t a = -40? to +85? -3 2 shdn input threshold shdn = in or gnd t a = +25?, i out = 100? v in = 2.5v to 5.5v t a = +25? shdn = gnd i out = 150ma i out = 100ma f = 100hz c out = 10?, f = 10hz to 100khz i out = 50ma i out = 100? i out = 100? i out = 100? to 120ma, c out = 1? i out = 150ma v in = 2.5v or (v out + 0.1v) to 6.5v, i out = 1ma conditions 0.05 na 0 100 i shdn shdn input bias current 0.4 v il v 2.0 v ih 0.02 t a = +85? ? 0.005 1 i off shutdown supply current db 60 psrr output voltage ac power- supply rejection ratio ? rms 170 output voltage noise %/ma 0.01 ? v ldr load regulation %/v -0.15 0 0.15 ? v lnr line regulation -2 2 t a = +25? t a = +85? % -1.0 1.0 v 2.5 6.5 v in input voltage output voltage accuracy 165 110 220 mv 50 0.1 v in -v out dropout voltage (note 2) ma 150 i out maximum output current ma 160 390 i lim current limit ? 85 180 i q ground pin current 100 units min typ max symbol parameter i out = 100? to 120ma i out = 100? shutdown
MAX8875 150ma, low-dropout linear regulator with power-ok output _______________________________________________________________________________________ 3 0 40 20 80 60 100 120 023 1 456 ground pin current vs. input voltage MAX8875toc01 input voltage (v) ground pin current ( a) i out = 0 i out = 150ma 85 100 95 90 105 110 115 060 45 15 30 75 90 105 120 135 150 ground pin current vs. output load MAX8875toc02 output load (ma) ground pin current ( a) v in = 3.5v v in = 5.0v 85 100 105 95 90 110 115 120 060 45 15 30 75 90 105 120 135 150 ground pin current vs. output load MAX8875toc03 output load (ma) ground pin current ( a) v in = v out(nominal) + 0.5v v out = 5.0v MAX8875euk50 v out = 3.0v MAX8875euk30 typical operating characteristics (MAX8875euk30, v in = +3.6v, c in = c out = 1?, shdn = in, t a = +25?, unless otherwise noted.) electrical characteristics (continued) (v in = v out(nominal) + 1v, shdn = in, t a = -40? to +85?, unless otherwise noted. typical values are at t a = +25?.) (note 1) note 1: limits are 100% production tested at t a = +25?. limits over the operating temperature range are guaranteed through correlation using statistical quality control (sqc) methods. note 2: dropout voltage is defined as v in - v out , when v out is 100mv below the value of v out for v in = v out + 0.5v. applies only for output voltages 2.5v. thermal shutdown temperature t shdn 170 ? thermal shutdown hysteresis ? t shdn 20 ? parameter symbol min typ max units conditions pok output leakage current 1 ? 0 v pok 6.5v, v out in regulation pok output voltage low v ol 0.4 v i sink = 1ma -3 -5 -8 1 - v out /v out(nominal) 100, i out = 0, v out falling, v out 2.5v -5.3 in dropout, v out falling, v out 2.5v power-ok voltage threshold v pok 1 % hysteresis, i out = 0 -8.5 -10.5 -13.5 1 - v out /v out(nominal) 100, i out = i lim , v out falling, v out < 2.5v -7 -15 thermal protection power-ok output t a = 0? to +85? t a = -40? to +85?
MAX8875 150ma, low-dropout linear regulator with power-ok output 4 _______________________________________________________________________________________ typical operating characteristics (continued) (MAX8875euk30, v in = +3.6v, c in = c out = 1?, shdn = in, t a = +25?, unless otherwise noted.) 2.90 2.95 3.00 3.05 3.10 -40 10 -15 35 60 85 output voltage vs. temperature MAX8875toc07 temperature (?) output voltage (v) v in = 3.6v or 5.0v i out = 0 v in = 3.6v i out = 150ma v in = 5.0v i out = 150ma 0 150 100 50 200 250 045 30 15 105 90 75 60 150 135 120 dropout voltage vs. output load MAX8875toc08 output load (ma) dropout voltage (mv) t a = +25 c t a = +85 c t a = -40 c 0 0.01 0.1 1 10 100 1000 power-supply rejection ratio vs. frequency 10 20 30 40 50 60 70 MAX8875toc09 frequency (khz) psrr (db) c out = 10 f c out = 1 f 10 0.01 0.1 10 100 output noise spectral density vs. frequency 0.1 1 MAX8875toc10 frequency (khz) output noise spectral density ( v/ hz ) 1 c out = 10 f i out = 50ma 10ms/div output noise v out 500 v/div MAX8875toc11 f = 10hz to 100khz c out = 10 f i out = 50ma 60 80 70 100 90 120 110 130 -40 10 -15 356085 ground pin current vs. temperature MAX8875toc04 temperature ( c) ground pin current ( a) v in = 5.0v i out = 150ma v in = 3.6v i out = 150ma v in = 3.6v or 5.0v i out = 0 0 1.0 0.5 2.0 1.5 3.0 2.5 3.5 023 1 456 output voltage vs. input voltage MAX8875toc05 input voltage (v) output voltage (v) i out = 0 i out = 150ma 2.90 2.95 3.00 3.05 3.10 045 30 105 90 75 15 60 120 135 150 output voltage vs. output load MAX8875toc06 output load (ma) output voltage (v) v in = 3.6v v in = 5.0v 10 s/div line-transient response i out = 50ma 5v 4v 3.00v 2.98v 3.02v v in v out MAX8875toc13
MAX8875 150ma, low-dropout linear regulator with power-ok output _______________________________________________________________________________________ 5 100 s/div shutdown delay MAX8875euk30, r out = 60 ? 3v 0 0 2v v out 1v/div MAX8875toc16 v shdn 1v/div 200 s/div pok output r pok = 100k ? 0 0 2v 3v 4v v pok 2v/div v out 2v/div MAX8875toc17 v in 1v/div 10ms/div pok startup response 5.0v 2.5v 0 0 0 5.0v v pok 2.5v/div v out 2.5v/div MAX8875toc18 v in 2.5v/div r pok = 100k ? 10 s/div pok and shutdown response 2v 0 2v 0 0 4v v pok 2v/div v out 2v/div MAX8875toc19 v shdn 2v/div r load = 60 ? r pok = 100k ? typical operating characteristics (continued) (MAX8875euk30, v in = +3.6v, c in = c out = 1?, shdn = in, t a = +25?, unless otherwise noted.) 10 s/div load-transient response v in = v out + 0.5v, i out = 0 to 50ma 3.01v 3.00v 2.99v 0 50ma v out i load MAX8875toc14 10 s/div load-transient response near dropout v in = v out + 0.1v, i out = 0 to 50ma 3.01v 3.00v 2.99v 0 50ma v out i load MAX8875toc15
_______________detailed description the MAX8875 is a low-dropout, low-quiescent-current linear regulator designed primarily for battery-powered applications. the device supplies loads up to 150ma and is available with preset output voltages of 1.5v, 2.5v, 2.7v, 3.0v, 3.3v, or 5.0v. as illustrated in figure 1, the MAX8875 consists of a 1.25v reference, error amplifier, p-channel pass transistor, power-ok com- parator, and internal feedback voltage divider. the 1.25v bandgap reference is connected to the error amplifier? inverting input. the error amplifier compares this reference with the feedback voltage and amplifies the difference. if the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled lower, which allows more current to pass to the output and increases the output voltage. if the feedback volt- age is too high, the pass-transistor gate is pulled up, allowing less current to pass to the output. the output voltage feeds back through an internal resistor voltage divider connected to the out pin. additional blocks include a current limiter, reverse- battery protection, thermal sensor, and shutdown logic. MAX8875 150ma, low-dropout linear regulator with power-ok output 6 _______________________________________________________________________________________ figure 1. functional diagram regulator output. fixed 5.0v, 3.3v, 3.0v, 2.7v, 2.5v, or 1.5v output. sources up to 150ma. bypass with 1? (<0.2 ? typical esr) ceramic capacitor to gnd for v out 2.5v. bypass with 3.3? (<0.2 ? typ esr) ceramic capacitor to gnd for v out = 1.5v. out 5 power-ok output. active-low, open-drain output indicates an out-of-regulation condition. connect a 100k pull-up resistor to out for logic levels. if not used, leave this pin unconnected. pok 4 active-low shutdown input. a logic low reduces the supply current to below 1?. connect to in for normal operation. shdn 3 pin ground. this pin also functions as a heatsink. solder to a large pad or the circuit-board ground plane to maximize power dissipation. gnd 2 regulator input. supply voltage can range from 2.5v to 6.5v. bypass with 1? to gnd (see the capacitor selection and regulator stability section). in 1 function name pin description shutdown logic error amp 1.25v ref 95% ref p gnd in shdn MAX8875 thermal sensor reverse- battery protection mos driver with i limit pok out pok
output voltage the MAX8875 is supplied with factory-set output volt- ages of 1.5v, 2.5v, 2.7v, 3.0v, 3.3v, or 5.0v. the part number? two-digit suffix identifies the nominal output voltage. for example, the MAX8875euk33 has a preset output voltage of 3.3v (see output voltage selector guide ). internal p-channel pass transistor the MAX8875 features a 1.1 ? (typ) p-channel mosfet pass transistor. this provides several advantages over similar designs using pnp pass transistors, including longer battery life. the p-channel mosfet requires no base drive, which reduces quiescent current signifi- cantly. pnp-based regulators waste considerable current in dropout when the pass transistor saturates. they also use high base-drive currents under large loads. the MAX8875 does not suffer from these prob- lems and consumes only 100? of quiescent current whether in dropout, light-load, or heavy-load applica- tions (see typical operating characteristics ). power-ok output (pok) when the output voltage goes out of regulation?s dur- ing dropout, current limit, or thermal shutdown?ok goes low. pok is an open-drain n-channel mosfet. to obtain a logic-level output, connect a pull-up resistor from pok to out. to minimize current consumption, make this resistor as large as practical. a 100k ? resistor works well for most applications. a capacitor to gnd may be added to generate a power-on-reset (por) delay. the pok function is not active during shutdown. pok also provides a power-on-reset function that can operate down to v in 1v. see pok startup response in the typical operating characteristics . current limit the MAX8875 includes a current limiter that monitors and controls the pass transistor? gate voltage, limiting the output current to 390ma (typ). for design purpos- es, consider the current limit to be 160ma min to 600ma max. the output can be shorted to ground for an indefinite period of time without damaging the part. thermal-overload protection when the junction temperature exceeds t j = +170?, the thermal sensor signals the shutdown logic, turning off the pass transistor and allowing the ic to cool. the thermal sensor will turn the pass transistor on again after the ic? junction temperature cools by 20?, resulting in a pulsed output during continuous thermal-overload conditions.thermal-overload protection is designed to protect the MAX8875 in the event of fault conditions. for continuous operation, do not exceed the absolute maxi- mum junction-temperature rating of t j = +150?. operating region and power dissipation the MAX8875? maximum power dissipation depends on the thermal resistance of the case and circuit board, the temperature difference between the die junction and ambient air, and the rate of air flow. the power dis- sipation across the device is p = i out (v in - v out ). the maximum power dissipation is: p max = (t j - t a ) / ( jb + ba ) where t j - t a is the temperature difference between the MAX8875 die junction and the surrounding air, jb (or jc ) is the thermal resistance of the package, and ba is the thermal resistance through the printed circuit board, copper traces, and other materials to the sur- rounding air. the MAX8875? ground pin (gnd) performs the dual function of providing an electrical connection to system ground and channeling heat away. connect gnd to the system ground using a large pad or ground plane. reverse-battery protection the MAX8875 has a unique protection scheme that lim- its the reverse supply current to 1ma when either v in or v shdn falls below ground. the circuitry monitors the polarity of these two pins and disconnects the internal circuitry and parasitic diodes when the battery is reversed. this feature prevents device damage. __________applications information capacitor selection and regulator stability for stable operation over the full temperature range and with load currents up to 150ma, use a 1? (min) ceramic output capacitor with an esr <0.2 ? for v out 2.5v, or an equivalent 3.3? ceramic output capacitor for v out = 1.5v. to reduce noise and improve load- transient response, stability, and power-supply rejec- tion, use large output capacitor values, such as 10?. note that some ceramic dielectrics exhibit large capac- itance and esr variation with temperature. with dielectrics such as z5u and y5v, it may be necessary to increase the capacitance by a factor of 2 or more to ensure stability at temperatures below t a = -10?. with x7r or x5r dielectrics, 1? should be sufficient at all operating temperatures for v out 2.5v. for a pin-com- patible, functionally equivalent device for use with a higher esr output capacitor, see the max8885. MAX8875 150ma, low-dropout linear regulator with power-ok output _______________________________________________________________________________________ 7
MAX8875 psrr and operation from sources other than batteries the MAX8875 is designed to deliver low dropout voltages and low quiescent currents in battery-powered systems. power-supply rejection is 60db at low frequencies. see the power-supply rejection ratio vs. frequency graph in the typical operating characteristics . improve supply-noise rejection and transient response by increasing the values of the input and output bypass capacitors. the typical operating characteristics show the MAX8875? line- and load-transient responses. dropout voltage for versions with the output voltage greater than the minimum input voltage (2.5v), the regulator? minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. in battery- powered systems, this will determine the useful end-of- life battery voltage. because the MAX8875 uses a p-channel mosfet pass transistor, its dropout voltage is a function of drain-to-source on-resistance (r ds(on) ) multiplied by the load current (see typical operating characteristics ): v dropout = v in - v out = r ds(on) ? i out chip information transistor count: 266 150ma, low-dropout linear regulator with power-ok output 8 _______________________________________________________________________________________
maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. 9 _____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 2000 maxim integrated products printed usa is a registered trademark of maxim integrated products. sot5l.eps package information 150ma, low-dropout linear regulator with power-ok output MAX8875
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