www.a-power.com.tw 1 advanced power electronics corp. ap431a features ? precision reference voltage ap431a : 2.495v 0.5% ? sink current capability: 200ma ? minimum cathode current for regulation: 300 a ? equivalent full-range temp coefficient: 30 ppm/ o c ? fast turn-on response ? low dynamic output impedance: 0.2 ? ? programmable output voltage to 36v ? low output noise. ? packages: to-92,sot-23, sot-25 and sop-8 ? rohs comp liant & halogen free product description the ap431a are 3-terminal adjustable precision shunt regulators with guaranteed temperature stability over the applicable extended commercial temperature range. the output voltage may be set at any level greater than 2.495v(v ref ) up to 36v merely by selecting two external resistors that act as a voltage divider network. these devices have a typical output impedance of 0.2 ? . active output circuitry provides very sharp turn-on characteristics, making these devices excellent improved replacements for zener diodes in many applications. the precise (+/-) 1% reference voltage tolerance of the ap431a make it possible in many applications to avoid the use of a variable resistor, consequently saving cost and eliminating drift and reliability problems associated with it. ordering information typical application circuit + + + + + + + + r2 r1 v out v in v out = (1+r1/r2)v ref precision regulator c in c out ap431 ap431a adjustable precision shunt regulator a p 4 3 1 a x - x package reference voltage t : to-92 n/nr : sot-23 y : sot-25 m : s op -8 tolerance : a : +/- 0.5% b : +/- 1% g: sot-89 sot-89 20130401v6.2
www.a-power.com.tw 2 advanced power electronics corp. ap431a block diagram ref (r) v ref + - anode (a) cathode (c) symbol pin configuration order number pin configuration ( top view ) ap431at ( to-92 ) 3 cathode 2 anode 1 ref ap431am ( so -8 ) 1 2 3 4 8 6 anode anode nc anode anode nc ref order number pin configuration ( top view ) ap431an ( sot-23 ) cathode anode ref ap431ay ( sot-23-5l ) nc anode 3 2 1 1 2 5 4 1 3 ref n c 7 5 cathode cathode cathode nc anode 1 2 5 4 1 3 ref n c cathode ap431ay5 ( sot-23-5l ) anode ref 2 3 1 cathode ap431ag ( so t-89 ) 2 cathode (c) ref (r) anode (a) ap431anr ( sot-23 ) anode ref 3 2 1 cathode r thj a = 160 o c/w rthj l=60 o c/w rthja= 208 o c/w rthjc= 50 o c/w rthja= 25 0 o c/w rthjc=1 1 0 o c/w rthja= 50 0 o c/w rthjc=1 8 0 o c/w rthja= 500 o c/w rthjc= 18 0 o c/w rthja= 50 0 o c/w rthjc=1 8 0 o c/w rthja= 50 0 o c/w rthjc=1 8 0 o c/w
www.a-power.com.tw 3 advanced power electronics corp. ap431a absolute maximum ratings cathode voltage ????????????......?.........................?...???????????...???.36v continuous cathode current ??????????.??.............?................?????.... -10ma ~ 250ma reference input current range ?????..???..............??.................................????.?....... 10ma operating te mperature range ????.????..??.??.....??????...........???......-40 o c ~ 85 o c lead temperature??????????.????.??.????....????????.........?............ 260 o c storage temperature ???????????......?....?.............??????..??...?....... -65 o c ~ 150 o c power dissipation (notes 1. 2) to-92 package ?.????..?????????....????.....? 0.78w sot-23 package .?...????..?????.......???????? 0.25w sot-25 package????????...?????.????.???..0.25w sop-8 package??????.???????????????? 0.6w note 1: tj, max =150 o c note 2: ratings apply to ambient temperature at 25 o c sop-89 package............................................................................... 0.5w
www.a-power.com.tw 4 advanced power electronics corp. ap431a note 3. deviation of reference input voltage, v dev , is defined as the maximum variation of the reference over the full temperature range. the average temperature coefficient of the reference input voltage " v ref is defined as: 1 2 6 ref dev ref t t 10 ) c) (25 v v ( v ? ? = ) c ppm ? ? = + ? ? =
www.a-power.com.tw 5 advanced power electronics corp. ap431a typical performance characteristics cathode current vs cathode voltage -100 0 100 -1.5 -0.5 0.5 1.5 2.5 cathode voltage(v) cathode current(ma) v ka =vref ta=25 o c cathode current (ua) vs cathode voltage -1 cathode voltage(v) cathode current(ua) -200 200 400 600 0 -0.5 0 0.5 1 1.5 2 2.5 v ka =vref ta=25 o c reference voltage vs free-air temperature free-air tempeture ( o c) reference voltage(mv) 2480 2485 2490 2495 2500 -40 80 -30 -20 -10 0 10 20 30 40 50 60 70 reference input current vs free temperature free-air temperature( o c) reference input current (ua) 1 1.2 1.4 1.6 1.8 2 -50 -25 0 25 50 75 100 125 r1=10k i ka =10ma change in reference voltage vs cathode voltage 0 5 10 15 20 25 30 cathode volta g e ( v ) change in reference voltage (mv) -12 -10 -8 -6 -4 -2 0 i ka =10ma ta=25 o c
www.a-power.com.tw 6 advanced power electronics corp. ap431a typical performance characteristics(continued) + - + - output gnd 15k ? 8.25k ? 9f i ka 232 ? test circuit for voltage amplification small-signal voltage amplification vs. frequency 0 10 20 30 40 50 60 1k 10k 100k 1m 10m f-frequency-hz a v -small signal voltage amplification (db) i ka =10ma t a =25 o c + - i ka gnd output 1k ? 50 ? test circuit for reference impedance reference impedance vs. frequency 0.1 1 10 100 1k 10k 100k 1m 10m f-frequency-hz # zk a #$ reference impedance $% i ka =10ma t a =25 o c
www.a-power.com.tw 7 advanced power electronics corp. ap431a pulse response 0 1 2 3 4 5 6 -101234567 t-time- s input and output voltage-v input output gnd output 220 ? 50 ? test circuit for pulse response pulse generator f=100khz t a =25 o c + - 150 ? i ka v batt c l test circuit for curve a + - c l r1=10k ? r2 i ka 150 ? v batt test circuit for curve b, c, and d the areas under the curves represent conditions that may cause the device to oscillate. for curves b, c, and d, r2 and v+ were adjusted to establish the initial v ka and i ka conditions with c l =0.v batt and c l were then adjusted to determine the ranges of stability. stability boundary conditions ? 0 10 20 30 40 50 60 70 80 90 100 0.001 0.01 0.1 1 10 c l -load capacitance-f i ka -cathode current-ma a v ka =v ref b v ka =5v c v ka =10v d v ka =15v a b c d stable stable ta=25 o c
www.a-power.com.tw 8 advanced power electronics corp. ap431a application examples v in + low limit v ref (1 + r1b/r2b) +v be high limit v ref (1 + r1a/r2a) r1a r1b r2a r2b v be output on when low limint < v in < high limit fig.10 over-voltage / under-voltage protection circuit v in r cl i out i out = v ref / r cl fig.6 current limiter or current source i out v in i out = v ref / r s r s fig.7 constant-current sink fig.4 voltage monitor fig.5 delay timer v out = (1 + r1/r2) x v ref v in r1 r2 fig.8 higher-current shunt regulator v out v in puse r1 r2 l imit (1 + r1/r2) x v ref fig.9 crow bar v out v in on off r + v in delay = rc x ln( v in -v ref ) led on when low limit v in high limit low limit v ref (1+r1b/r2b) high limit v ref (1+r1a/r2a) r1a r2a v in r1b r2b
advanced power electronics corp. ap431a marking information so-8 sot-23-5l sot-23 sot-89 9 431am ywwsss part number date code (ywwsss) y last digit of the year ww week sss sequence package code r6&xx part number : a p431ay : r6 a p431ay5 : r65 id code : internal r6&xx part number : a p431an : r6 a p431anr : r6r id code : internal 4 3 1 a part number yww s date code (ywws) y:year ww week s sequence
advanced power electronics corp. ap431a marking information to-92 10 431a y wws part number date code (ywws) y:year ww week s sequence
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