ts2951/a 150ma ultra low dropout voltage regulator 1/10 version: d11 sop - 8 general description the ts2951/a are low power voltage regulators. thes e devices are excellent choice for use in battery-p owered applications such as cordless telephone, radio cont rol systems, and portable computers. the ts2951/a is features very low quiescent current (75ua typ.) and very low drop output voltage (typ. 40uv at light load and 380 mv at 100 ma). this includes a t ight initial tolerance of 1% (a version), extremely good load and line regulation 0.05% typ. and very low output temperature coefficient, making the ts2951/a useful as a low-power voltage reference. ts2951/a have other key additional feature. the err or flag output feature is used as power-on reset fo r warn of a low output voltage, due to following batteries on i nput. the logic-compatible shutdown input which ena ble the regulator to be switched on/off. the regulator outp ut voltage may be pin-strapped for a 5.0 & 3.3 & 3. 0 of programmed from 1.24v to 29v with external pair of resistors. using of as design, processing and testi ng techniques make ts2951/a superior over similar prod ucts. features output voltage available in 5v & 3.3v extremely low quiescent current low dropout voltage extremely tight load and line regulation very low temperature coefficient need only 1uf for stability use as regulator or reference stable with low-esr output capacitors current and thermal limiting error flag warns of output dropout logic-controlled electronic shutdown additional voltage tap output voltage sense output programmable from 1.24 to 29v ordering information part no. package packing ts2951cs xx rl sop-8 2.5kpcs / 13 reel ts2951acs xx rl sop-8 2.5kpcs / 13 reel note: where xx denotes voltage option, available are 50 = 5.0v 33 = 3.3v 30= 3.0v application battery powered systems smps post-regulator voltage reference portable consumer equipment absolute maximum rating parameter symbol limit unit input supply voltage v in - 0.3 ~ +30 v feedback input voltage vfeedback - 1.5 ~ +30 v shutdown input voltage vshutdown - 0.3 ~ +30 v error comparator output voltage verror - 0.3 ~ +30 v power dissipation pd internally limited w operating junction temperature range t j - 40 ~ +125 o c storage temperature range t stg -65 ~ +150 o c lead temperature (soldering 5 second) t stg 260 o c thermal resistance junction to ambient r ? ja 180 o c/w thermal resistance junction to case r ? jc 45 o c/w pin definition : 1. output 8. input 2. sense 7. fb 3. shutdown 6. voltage tap 4. ground 5. error flag
ts2951/a 150ma ultra low dropout voltage regulator 2/10 version: d11 electrical characteristics (v in =v out +1v, ta=25 o c, unless otherwise specified.) parameter test conditions (note 2) min typ max unit output voltage tj=25 o c ts2951 |0.985| 5.0 3.3 3.0 |1.015| v ts2951a |0.990| |1.010| full operating temp ts2951 |0.980| |1.020| ts2951a |0.988| |1.012| 100ua i l 100ma tj tj(max) ts2951 |0.975| |1.025| ts2951a |0.985| |1.015| output voltage temperature coefficient (note 1) ts2951 -- 50 150 ppm/ o c ts2951a -- 20 100 line regulation (note 3) 6v v in 30v (note 4) -- 0.04 0.2 % load regulation (note 3) 100ua i l 100ma -- 0.1 0.3 % dropout voltage (note 5) i l =100ua i l =100ma -- 50 380 80 450 mv mv ground current i l =100ua i l =100ma -- 75 8 120 12 ua ma dropout ground current v in = 4.5v, i l = 100ua -- 110 170 ua current limit v out = 0 -- 160 200 ma thermal regulation -- 0.05 0.2 %w output noise, 10hz to 100khz bypass=0.01uf (pins 7 to 1 ts2951/a) c l = 1uf c l = 200uf c l = 3.3uf -- -- -- 430 160 100 -- -- -- uv/ rms reference voltage (note6) ts2951 1.185 1.235 1.285 v ts2951a 1.19 1.27 feedback pin bias current -- 20 40 na reference voltage temperature coefficient (note 7) -- 20 -- ppm/ o c feedback pin bias current temperature coefficient -- 0.1 -- na/ o c output leakage current v oh = 30v -- 0.01 1 ua output low voltage v in = 4.5v, i ol = 400ua -- 150 250 mv upper threshold voltage (note 8) 40 60 -- mv power threshold voltage (note 8) -- 75 95 mv hysteresis (note 8) -- 15 -- mv output logic voltage low (regulator on) high(regulator off) -- 2.0 1.3 1.3 0.7 -- v shut down pin current vs = 2.4v vs = 30v -- 30 450 50 600 ua regulator output current in shutdown (note 9) -- 3 10 ua
ts2951/a 150ma ultra low dropout voltage regulator 3/10 version: d11 note: 1: output voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range. 2: unless otherwise specified all limits guaranteed for t j = 25 o c, vin= 6v, i l = 100ua and c l = 100uf. additional conditions for the 8-pin versions are feedback tied to 5v, 3.3v & 3v tap output sense (vout = 5v, 3.3v & 3v) and shutdown 0.8v. 3: regulation is measured at constant junction tempe rature, using pulse testing with a low duty cycle. changes in output voltage due to heating effects are covered u nder the specification for thermal regulation. 4: line regulation for the ts2951 is tested at 85 o c for i l = 1ma.for i l = 100ua and tj= 125 o c, line regulation is guaranteed by design to 0.2%. 5: dropout voltage is defined as the input to output d ifferential at which the output voltage drops 100mv below its nominal value measured at 1v differential at very l ow value of programmed output voltage, the minimum input supply voltage of 2v (2.3v over temperature) must b e taken in to account. 6: vref vout (vin-1v), 2.3 vin 30v, 100ua i l 100ma, tj tj(max) . 7: reference voltage temperature coefficient is defin ed as the worst case voltage change divided by the total temperature range. 8: comparator thresholds are expressed in terms of a v oltage differential at the feedback terminal below the nominal reference voltage measured at 6v input. to express these thresholds in terms of output voltage change, multiply by the error amplifier gain= vout / vref = (r1+r2) / r2. for example, at a programmed output voltage of 5v, the error output is guaranteed to go low when t he output drops by 95 mv x 5v / 1.250 = 384mv. thre sholds remain constant as a percent of vout as vout is var ied with the dropout warning occurring at typically 5% below nominal, 7.5% guaranteed. application hints external capacitors for the stability of the ts2951/a is requires a 1.0 uf(0.22uf is recommended for 3.0v & 3.3v) or greate r capacitor between output and ground. oscillation could occur without this capacitor. the tantalum or aluminum el ectrolytic works fine; could use the film type work but are no t cost efficient. for the operation of below -25 o c solid tantalum is recommended since the many aluminum type have elect rolytes the freeze at about -30 o c. the esr of about 5 or less and resonant frequency above 500khz are most i mportant parameter in the value of capacitor. the capacitors value can be increased without any limit . at lower values of output current, less output ca pacitance is required for stability. for the currents below 10ma the value of capacitor can be reduce to 0.33uf and 0.1uf for 1ma. more output capacitance needed for the 8-pin v ersion at voltage below 5v since it runs the error amplifier at lower gain. at worst case 3.3uf or greater must be used for condition of 100ma load at 1.250v output. the ts2951/a is not like other low dropout regulato rs will remain stable and regulation with no load i n addition to the internal voltage divider. this feature very imp ortant in application, it is like cmos ram keep-ali ve. the ts2951/a output voltage is set with minimum load of 1ua and external resistors. if at the input ofts2951/a connected to battery or between ac filter capacitor and input is 10 inches wire then 1uf tantalum or aluminum electrolytic capacitor should be connected between input and ground. instability can occur if stray capacitor to feedback terminal pin 7 of the t s2951/a. this could cause more problems when using higher value of external to set the output voltage. to fix this problem the 100pf capacitor between output an d feedback and increasing output capacitance to 3.3uf.
ts2951/a 150ma ultra low dropout voltage regulator 4/10 version: d11 application hints (continued) reducing output noise it could be an advantage to reduce the ac noise pre sent at the output. one method is to reduce the reg ulator bandwidth by increasing the value of the output cap acitor. this is the only method that noise could re duce on the ts2951/a, but is relatively inefficient, as increas ing capacitor from 1uf to 220uf only decreases the noise from 430uv to 160uvrms for a 100khz bandwidth at 5v outp ut. noise could be also reduced by fourfold by a by pass capacitor across r1 since it reduces the high frequ ency gain from 4 to unity. pick cbypass= 1 / 2 r1 * 200hz or choose 0.01uf when doing this, the outpu t capacitor must be increased to 3.3uf to maintain stability. these change the outpu t noise from 430uv/rms for a 100 khz bandwidth 5v, 3.3v & 3v output. with the bypass capacitor added, noise no l onger scales with output voltage so that improvemen ts are more dramatic higher output voltage. error detection comparator output the compactor produces a logic low output whenever the ts2951/a output falls of regulation by more tha n around 5%. this is around 60 mv offset divided by the 1.23 5 reference voltage. thus trip remains 5% below nom inal regardless of the programmed output voltage of the regulator. the figure 1 shows the timing diagram de picting the error signal and the regulator output voltage as th e ts2951/a input is ramped up and down. the error s ignal becomes low at around 1.3v input,it goes high aroun d 5v input (input voltage at which vout=4.75v). the ts2951/a dropout voltage depending on the load, the input vo ltage trip point around 5v will vary with load curr ent. the output voltage trip point is around 4.75v, it does not cha nge with load. the error comparator has an open-col lector output which requires an external pull-up resistor. depend ing on the system requirement, the resistor maybe r eturned to 5 or 3.3v output or other supply voltage depending to the system requirements. for determining the size of the resistor, note that the output is sinking 400ua, th is value adds to battery drain in a low better cond ition, recommended values 100k to 1m . if the output is unused this resistor is not requ ired. programming the output voltage the ts2951/a output voltage is programmable for any value from it reference voltage of 1.235v and it m aximum rating of 30v. for example for 5 volt needs to pin- strapped and using the internal voltage divider by tying pin 1 to 2 and pin 7 to pin 6. refer to figure 2, there are tw o external resistor required for this programming. refer to the below equation for the programming the output volta ge: volt=vref x (1+r1\r2)+i fb * r1 the vref is 1.235v and i fb is the feedback bias current, nominally -20na. the minimum recommended load current of 1ua forces an upper limit of 1.2m on value of r2, if no load presented the i fb produces error of typically 2% in vout which maybe eliminated at room temperature by trimming r1. to improve the accuracy chooses the va lue of r2=100k and this reduces the error by 0.17% and inc reases the resistor program current by 12ua. the ts 2951/a typically draw 60ua at no load with pin 2 open-circ uit, and this value does not look much.
ts2951/a 150ma ultra low dropout voltage regulator 5/10 version: d11 application hints (continued) figure 1. error output timing figure 2. adjust voltage block diagram and typical applications circuit
ts2951/a 150ma ultra low dropout voltage regulator 6/10 version: d11 electrical characteristics curve (ta = 25 o c, unless otherwise noted) figure 1. line regulation vs. input voltage figure 2. load regulation vs. output current figure 3. ground pin current vs. output current figure 4. ground pin current vs. input voltage figure 5. dropout voltage vs. output current figure 6. load transient response
ts2951/a 150ma ultra low dropout voltage regulator 7/10 version: d11 sop-8 mechanical drawing marking diagram xx = voltage code ( 50 = 5.0v, 33 = 3.3v, 30 = 3.0v ) y = year code m = month code ( a =jan, b =feb, c =mar, d =apl, e =may, f =jun, g =jul, h =aug, i =sep, j =oct, k =nov, l =dec) l = lot code sop-8 dimension dim millimeters inches min max min max. a 4.80 5.00 0.189 0.196 b 3.80 4.00 0.150 0.157 c 1.35 1.75 0.054 0.068 d 0.35 0.49 0.014 0.019 f 0.40 1.25 0.016 0.049 g 1.27bsc 0.05bsc k 0.10 0.25 0.004 0.009 m 0o 7o 0o 7o p 5.80 6.20 0.229 0.244 r 0.25 0.50 0.010 0.019
ts2951/a 150ma ultra low dropout voltage regulator 8/10 version: d11 notice specifications of the products displayed herein are subject to change without notice. tsc or anyone on its behalf, assumes no responsibility or liability for any erro rs or inaccuracies. information contained herein is intended to provide a product description only. no license, express or implied, to any intellectual property rights is granted by this document. except as provided in tscs terms and co nditions of sale for such products, tsc assumes no liability wh atsoever, and disclaims any express or implied warr anty, relating to sale and/or use of tsc products includi ng liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, cop yright, or other intellectual property right. the products shown herein are not designed for use in medical, life-saving, or life-sustaining applica tions. customers using or selling these products for use i n such applications do so at their own risk and agr ee to fully indemnify tsc for any damages resulting from such i mproper use or sale.
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