ts1431 adjustable precision shunt regulator 1 / 10 version: d14 sot - 23 general description ts1431 series integrated circuits are three - terminal programmable shunt regulator diodes. these monolithic ic voltage references operate as a low temperature coefficient zener which is programmable from v ref to 36 vol ts with two external resistors. these devices exhibit a wide operating current range of 1.0 to 100ma with a typical dynamic impedance of 0.22 . the characteristics of these references make them excellent replacements for zener diodes in many application s such as digital voltmeters, power supplies, and op amp circuitry. the 2.5 v reference makes it convenient to obtain a stable reference from 5.0 v logic supplies, and since the ts1431 series operates as a shunt regulator, it can be used as either a positive or negative s tage reference. features precision reference voltage ts1431a 2.495v?% ts1431b 2.495v?.5% equivalent full range temp. coefficient: 50ppm/ c programmable output voltage up to 36v fast turn - on response sink current capabili ty of 1~100ma low dynamic output impedance: 0.2 low output noise ordering information part no. package packing ts1431 x cx rf sot - 23 3k pcs / 7 reel ts1431 x cx rfg sot - 23 3k pcs / 7 reel note: ??denote for green product where xx denotes volta ge tolerance a: ?%, b: ?.5% application voltage monitor delay timmer constant current source/sink high - current shunt regulator crow bar over - voltage / under - voltage protection block diagram absolute maximum rating s ( t a = 25 o c unless otherw ise noted) parameter symbol limit unit cathode voltage v ka 36 v continuous cathode current range i ka 1 ~ +1 0 0 ma reference input current range i ref - 0.05 ~ +10 ma power dissipation p d 0.30 w junction temperature t j +150 o c operating temperature rang e t opr 0 ~ +70 o c storage temperature range t stg - 65 ~ +150 o c pin definition : 1. cathode 2. reference 3. anode
ts1431 adjustable precision shunt regulator 2 / 10 version: d14 recommend ed operating condition parameter symbol limit unit cathode voltage (note 1) v ka ref ~ 36 v continuous cathode current range i k 1 ~ 100 ma electrical charac teristics parameter s ymbo l test conditions m in t yp m ax u nit reference v oltage ts1431 a v ref v ka =v ref , i k =10ma (figure 1) t a = 25 o c 2.475 2.495 2.525 v ts1431b 2.487 2.513 deviation of reference input voltage ? v ref v ka = v ref , i k =10ma (figure 1) t a = full range -- 3 17 mv radio of change in vref to c hange in c athode v oltage ? v ref /? v ka i ka =10ma , v ka = 10 v to v ref v ka = 36 v to 10v (figure 2) -- -- - 1.4 - 1.0 - 2.7 - 2.0 mv/v reference input current i ref r1=10k , r2= , i ka =10ma t a = full range (figure 2) -- 0.7 4.0 a deviation of reference input current, over temp. ? i ref r1=10k , r2= , i ka =10ma t a = full range (figure 2) -- 0.4 1.2 a off - state c athode c urrent i ka ( o ff ) v ref =0 v (figure 3), v ka = 36 v -- -- 1.0 a dynamic output i mpedance | z ka | f<1khz, v ka = v ref i ka = 1m a to 100ma (figure 1) -- 0.2 2 0.5 minimum operating cathode current i ka ( min ) v ka = v ref (figure 1) -- 0.4 0.6 m a * the deviation parameters ? v re f and ? i ref are defined as difference between the maximum value and minimum value obtained over the full operating ambient temperature range that applied. * the average temperature coefficient of the reference input voltage, v ref is defined as: where: t2 - t1 = full temperature change. v ref can be positive or negative depending on whether the slope is positive or negative. example: maximum v ref =2.496v at 30 o c, minimum v ref =2.492v at 0 o c, v ref =2.495v at 25 o c, t=70 o c v ref | = [ 4mv / 2495mv ] * 10 6 / 70 o c 23ppm/ o c because minimum v ref occurs at the lower temperature, the coefficient is positive. * the dynamic impedance z ka is defined as: | z ka | = v ka / i ka * when the device operating with two externa l resistors, r1 and r2, (refer to figure 2) the total dynamic impedance of the circuit is given by: | z ka | = v / i | z ka | * ( 1 + r1 / r2)
ts1431 adjustable precision shunt regulator 3 / 10 version: d14 test circuits figure 1: v ka = v ref figure 2: v ka > v ref figure 3: off - st ate current additional information stability when the ts 1 431a /1431b is used as a shunt regulator, there are two options for selection of c l , are recommended for optional stability: a) no load capacitance across the device, decouple at the load. b) large capac itance across the device, optional decoupling at the load. the reason for this is that ts 1 431a/ 1 431b exhibits instability with capacit ances in the range of 10nf to 1 f (approx.) at light cathode current up to 3ma (typ). the device is less stable the lower t he cathode voltage has been set for. therefore while the device will be perfectly stable operating at a cathode curre nt of 10ma (approx.) with a 0.1 f capacitor across it, it will oscillate transiently during start up as the cathode current passes through the instability region. select a very low capacitance, or alter natively a high capacitance (10 f) will avoid this issue altogether. since the user will probably wish to have local decoupling at the load anyway, the most cost effective method is to use no c apacitance at all directly across the device. pcb trace/via resistance and inductance prevent the local load decoupling from causing the oscillation during the transient start up phase. note: if the ts 1 431a/ 1 431b is located right at the load, so the load decoupling capacitor is directly across it, then this capacitor will have to be 1nf or 10 f. applications examples figure 4: voltage monitor figure 5: output control for three terminal fixed regulator
ts1431 adjustable precision shunt regulator 4 / 10 version: d14 applications examples (continue) figure 6: shunt regulator figure 7: high current shunt regulator figure 8: serie s pass regulator figure 9: constant current source figure 10: triac crowbar figure 11: scr crowbar
ts1431 adjustable precision shunt regulator 5 / 10 version: d14 applications examples (continue) vin vout vref 0.74v figure 12: single - supply comparator with temperature - compensated th reshold figure 13: constant current sink figure 14: delay timer
ts1431 adjustable precision shunt regulator 6 / 10 version: d14 typical performance characteristics test circuit for voltage amplification figure 1 5 : small - signal voltage gain and phase shirt vs. frequency test circ uit for reference impedance figure 1 6 : reference impedance vs. frequency
ts1431 adjustable precision shunt regulator 7 / 10 version: d14 typical performance characteristics (continue) 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 then were adjusted to determine the ranges of st ability. test circuit for curve a test circuit for curve b, c and d figure 1 7 : stability boundary condition test circuit for pulse response, ik=1ma figure 1 8 : pulse response
ts1431 adjustable precision shunt regulator 8 / 10 version: d14 electrical characteristics figure 1 9 : reference voltage vs. temperature figure 20 : reference current vs. temperature figure 2 1 : cathode current vs. cathode voltage
ts1431 adjustable precision shunt regulator 9 / 10 version: d14 sot - 23 mechanical drawing unit: millimeters marking diagram 1 = device code x = tolerance code ( a = 1%, b = 0.5 % ) 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) = month code for halogen free product ( o =jan, p =feb, q =mar, r =apl, s =may, t =jun, u =jul, v =aug, w =sep, x =oct, y =nov, z =dec ) l = lot code
ts1431 adjustable precision shunt regulator 10 / 10 version: d14 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 errors 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 tsc? terms and conditions of sale for such products, t sc assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of tsc products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, c opyright, or other intellectual property right. the products shown herein are not designed for use in medical, life - saving, or life - sustaining applications. customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify tsc for any damages resulting from such improper use or sale.
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