100ma low dropout voltage regulators LM2950/1 features high accuracy output voltage guaranteed 100 ma output very low quiescent current extremely tight load and line regulation very low temperature coefficient current and thermal limiting low dropout voltage need only 1uf for stability error flag warns of output dropout pin 1 : output logi-control electronic shutdown pin 2 : ground output programmable from 1.24 to 29v pin 3 : input moisture sensitivity level 3 applications ordering information high-efficiency linear regulator, voltage reference battery powered systems portable consumer equipment portable / parm, desktop / notebook computers (xx= 1.5, 1.8, 2.8, 2.85, 3.0, 3.3, 5.0v, portable instrumentation, cordless telephones adjustable) automotive electronics, radio control systems smps post-regulator, avionics description the LM2950/1 is a low power voltage regulator. this device excellent choice for use in battery powered application such as cordless telephone, radio control systems, and portable computers. the LM2950/1 features very low quiescent current (75 ? typ.) and very low drop output voltage (typ. 400 ? at light load and 380 ? at 100 ? ). this includes a tight initial tolerance of 0.5% typ., extremely good load and line regulation of 0.05% typ., and very low output temperature coefficient, making the LM2950/1 useful as a low-power voltage reference. the error flag output feature is used as power-on reset for warn of a low output voltage, due to following batteries on input. other feature is the logic-compatible shutdown input which enable the regulator to be switched on and off. the LM2950/1 is available in 8-pin plastic packages. the regulator output voltage may be pin-strapped for a -xx volt or programmed from 1.24 volt to 29 volts with external pair of resistors. the LM2950/1 is offered in 3-pin to-92 package compatible with other fixed regulator. feb 2009 - rev. 1.2 htc lm2951d-xx sop-8 ? 1 ? LM2950-xx to-92 pkg device to- 92 pkg sop- 8 pkg pin : 1. output 2. sense 3. shutdown 4. ground 5. error 6. tap 7. feedback 8. input 1 2 3
100ma low dropout voltage regulators LM2950/1 block diagram and typical applications (LM2950) block diagram and typical applications (lm2951) absolute maximum ratings lead temperature (soldering, 5 seconds) storage temperature range operating junction temperature range input supply voltage feedback input voltage shutdown input voltage error comparator output feb 2009 - rev. 1.2 htc -0.3 to +30v -0.3 to +30v power dissipation -1.5 to +30v -65 to +150 -55 to +150 -0.3 to +30v internally limited 260 ? 2 ? - 100? max input output ground unregulated dc + + - 1.23v reference 60k? error amplifier + 1? v out +
100ma low dropout voltage regulators LM2950/1 electrical characteristics (at t a =25 , v in =15v, unles otherwise specified) -25 t j 85 0.985 v 0 1.015 v 0 full operating temperature 0.980 v 0 1.020 v 0 output voltage 100 ? i l 100 ? ,t j t jmax 0.976 v 0 1.024 v 0 output voltage temperature coefficient (note 1) line regulation (note 3) v 0 +1v v in 30v load regulation (note 3) 100 ? i l 100 ? i l =100 ? i l =100 ? electrical characteristics (at t a =25 , v in =15v, unles otherwise specified) i l =100 ? i l =100 ? dropout ground current v in =v 0 -0.5v, i l =100 ? current limit v out =0 thermal regulation c l =1 ? c l =200 ? c l =3.3 ? (bypass=0.01 ? pins 7 to 1 error comparator output leakage current v oh =30v output low voltage v in =4.5v, i ol =400 ? upper threshold voltage (note 6) lower threshold voltage (note 6) hysteresis (note 6) shutdown input low (regulator on) high (regulator off) v s =2.4v v s =30v (note 7) feb 2009 - rev. 1.2 htc ? 3 ? 2.0v v out 3.3v regulator output current shutdown 20 30 v out =5.0v 3.3v v out 5.0v 2 1.3 0.7 8 shutdown pin input current input logic voltage ground current output noise, 10hz to 100khz 110 160 75 output voltage v 0 0.04 dropout voltage (note 4) 50 50 0.1 vr ? 120 12 170 250 ? ? ? %/w 0.2 75 0.05 15 430 160 ? 100 1.0 250 ? ? 15 0.01 150 40 v ? 30 3 50 600 10 450 60 parameter conditions (note 2) min typ max units parameter units v v 0 conditions (note 2) min typ max 150 ppm/ 0.4 % 380 450 0.3 % 80 ?
100ma low dropout voltage regulators LM2950/1 note 1 : output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total tem perature range. note 2 : unless otherwise specified all limits guaranteed for t j = 25 , v in = v 0 +1v, i l = 100 ? and c l = 1 ? . additional condition for the 8-pin versions are feedback tied to -xx v tap and output tied to output sense (v out =xx v) and v shoutdown 0.8v note 3 : regulations is measured at constant junction temperature, using pulse testing with a low duty cycle. changes in output voltage due to heating effects are covered under the specification for thermal regulation. note 4 : dropout voltage is defined as the input to output differential at which the output voltage drops 100 ? below its nominal value measured at 1v differential. at very low values of programmed output voltage, the minimum input supply voltage(2.3v over temperature ) must be taken into account. note 5 : v ref v out (v in -1v), 2.3v v in 30v, 100 ? i l 100 ? , t j t jmax note 6 : comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal refe rence voltage measured at v out +1v input. to express these thresholds in terms of output voltage changed, multiply by the error amplifier gain = v out /v ref = (r1+r2)/r2. for example, at a programmed output voltage of 5v, the error output is guaranteed to go low when the output drops by 95 ? x 5v / 1.235v = 384 ? . thresholds remain constant as a percent v out as v out is varied, with the dropout warning occurring at typically 5% below nominal, 7.5% guaranteed. note 7 : v shutdown 2v, v in 30v, v out =0, feed-back pin tied to -xx v tap. feb 2009 - rev. 1.2 htc ? 4 ?
|
