1 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier features temperature-compensated: 50 ppm/?c 0.25% to 2.0% bandgap offered internal amplifier with 150 ma capability multiple temperature ranges low frequency dynamic output impedance: < 150 m? low output noise description the as432 is a three terminal adjustable shunt regulator utilizing an accurate 1.24v bandgap reference. the as432 is functionally similar to an as431 except for its lower reference voltage, making it usable in a wide variety of low voltage applications. because of its robust bipolar technology, the as432 handles a wide range of cur- rent, and holds off more than 18v so its use is not limited to low power, low volt- age systems. significant care has been taken to provide adequate ac bandwidth to allow the as432 as an amplifier in control systems and power electronics. semiconductor pin configuration ? top view ordering information cathode to-92 (lp) soic (d) anode reference reference anode anode n/c cathode anode anode n/c sot-89 (s) cathode anode reference 1 2 3 4 8 7 6 5 sot-23/5l (dbv) anode reference n/c n/c cathode sot-23/3l (vs) cathode reference anode circuit type: 1.24v precision adjustable shunt regulator/amplifier temperature range: a b c bandgap tolerance: 2 1 r5 r25 = 0 c to 70 c = 0 c to 105 c = ?0 c to +85 c = 2% = 1% = 0.5% = 0.25% packaging option: a b t 7 13 package style: d dbv lp s vs = ammo pack = bulk = tube = tape and reel (7" reel dia) = tape and reel (13" reel dia) = soic = sot-23/5l = to-92 = sot-89 = sot-23/3l as432 a 2 d 7
2 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier functional block diagram e + reference (r) anode (a) cathode (k) 1.24 v e + absolute maximum ratings parameter symbol rating units cathode-anode reverse breakdown v ka 18 v anode-cathode forward current i ak 1 a operating cathode current i ka 100 ma reference input current i ref 1 ma continuous power at 25 ? c p d t o-92 775 mw 8l soic 750 mw sot -89 1000 mw sot -23/3l/5l 200 mw junction t emperature t j 150 ? c storage t emperature t stg e65 to 150 ? c lead t emperature (soldering 10 sec.) t l 300 ? c stresses greater than those listed under absolute maximum ra tings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operati onal sec - tions of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may af fect reliability . recommended conditions parameter symbol rating unit cathode v oltage v ka v ref to 18 v cathode current i k 10 ma t ypical thermal resistances package q ja q jc t ypical derating t o-92 160 ? c/w 80 ? c/w 6.3 mw/ ? c soic 175 ? c/w 45 ? c/w 5.7 mw/ ? c sot -89 1 10 ? c/w 8 ? c/w 9.1 mw/ ? c sot -23/3l/5l 575 ? c/w 150 ? c/w 1.7 mw/ ? c
3 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier electrical characteristics electrical characteristics are guaranteed over the full junction temperature range (0e105 ? c). ambient temperature must be derated based upon power dissipation and package thermal characteristics. unless otherwise stated, test conditions are: v ka = v ref and i k = 10 ma. t est as432 (0.25%) as432 (0.5%) parameter symbol condition min. t yp. max. min. t yp. max. unit output v oltage v ref i k = 10 ma 1.237 1.240 1.243 1.234 1.240 1.246 v t j = 25 ? c v k = v ref line regulation ? v ref v ka = 1.25 to 15 v 28 50 28 50 mv load regulation ? v ref i k = 1 to 100 ma 3.9 6 3.9 6 mv t emperature deviation ? v ref 0 < t j < 105 ? c 5 10 5 10 mv reference input current i ref 2.3 6 2.3 6 a reference input current ? i ref 0 < t j < 105 ? c 0.14 0.6 0.14 0.6 a t emperature coef ficient minimum cathode i k(min) 0.2 1 0.2 1 ma current for regulation of f state leakage i k(min) v ref = 0 v , 0.04 500 0.04 500 na v ka = 15 v t est as432 (1.0%) as432 (2.0%) parameter symbol condition min. t yp. max. min. t yp. max. unit output v oltage v ref i k = 10 ma 1.228 1.240 1.252 1.215 1.240 1.256 v t j = 25 ? c v k = v ref line regulation ? v ref v ka = 1.25 to 15 v 28 50 28 50 mv load regulation ? v ref i k = 1 to 100 ma 3.9 6 3.9 6 mv t emperature deviation ? v ref 0 < t j < 105 ? c 5 12 5 12 mv reference input current i ref 2.3 6 2.3 6 a reference input current ? i ref 0 < t j < 105 ? c 0.14 0.6 0.14 0.6 a t emperature coef ficient minimum cathode i k(min) 0.2 1 0.2 1 ma current for regulation of f state leakage i k(min) v ref = 0 v , 0.04 500 0.04 500 na v ka = 15 v *t emperature deviation is defined as the maximum deviation of the reference over the given temperature range and does not imply an incremental deviation at any given temperature.
4 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier t est circuits figure 1a. t est circuit 1 figure 1b. t est circuit 2 figure 1c. t est circuit 3 r 1 r 2 i k v in v ka (v ref ) i ref i ref i k v in v ka = v ref i k (off) v in v ka t ypical performance curves *calculating a verage t emperature coef ficient (tc) 0 ? ?0 0.2 2000 0 0 0 15 0.021 mv/ c 0.008%/ c 8.0 ppm/ c 30 45 60 75 90 105 ppm mv % d v ref d t t emperature ( c) ?tc in mv/ c = ?tc in %/ c = d t a d t a x 100 d v ref (mv) v ref at 25 c d v ref ?tc in ppm/ c = d t a x 10 6 v ref at 25 c d v ref
5 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier t ypical performance figure 2 figure 4 figure 3 figure 5 v ka ?cathode v oltage (v) i k ?cathode current ( m a) ?.5 0 0.5 1.0 1.5 ?00 ?00 0 100 200 300 400 500 600 700 800 900 low current operating characteristics ?5 c 25 c 125 c i k ?cathode current (ma) v ka ?cathode v oltage (v) ? ? 0 1 2 ?00 ?5 ?0 ?5 0 25 50 75 100 125 150 175 high current operating characteristics v ka = v ref t emperature range ?5 to 125 c ?0 ?0 0 30 t a ?ambient t emperature ( c) 60 90 120 i z off ?off state cathode current (na) 100 10 1 0.1 0.01 off state leakage v ka = 15 v v ref = 0 v ?0 ?0 0 30 t a ?ambient t emperature ( c) 60 90 120 v ref ?reference v oltage (v) 1.27 1.26 1.25 1.24 1.23 1.22 1.21 1.20 1.19 reference v oltage vs ambient t emperature v ka = v ref i k = 10 ma v ref = 1.240 v at 25 c
6 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier t ypical performance curves figure 6 figure 8 figure 7 figure 9 ?0 ?0 0 30 t a ?ambient t emperature ( c) 60 90 120 i ref ?reference input current ( m a) 2.4 2.3 2.2 2.1 2.0 reference input current r1 = 10 k w r2 = i k = 10 ma 0 3 6 9 12 15 18 ?0 c 25 c 75 c 125 c v ka ?cathode v oltage (v) d v ref ?change in reference v oltage (mv) 0 ?0 ?0 ?0 ?0 ?0 reference v oltage line regulation i k = 10 ma t emperature range: ?5 to 125 c 10 100 1 k 10 k 100 k f ?frequency (hz) 70 60 50 40 30 20 10 0 noise v oltage nv/ hz noise v oltage v ka = v ref i k = 10 ma t a = 25 c ?0 ?0 0 30 t a ?free air t emperature ( c) 60 90 120 40 30 20 10 0 z ka ?dynamic impedance (m w ) low frequency dynamic output impedance v ka = v ref v ka = 1 to 100 ma f 1khz
7 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier t ypical performance curves figure 10 figure 1 1 100 10 1.0 z ka ?dynamic impedance ( w ) 0.1 0.01 1 k 10 k 100 k f ?frequency (hz) 1 m 10 m t a = 25 c i k = 1 to 100 ma dynamic output impedance 80 70 60 50 40 30 20 10 0 1 k 10 k 100 k 1 m 10 m f ?frequency (hz) 230 w i k a v ?small signal v oltage gain (db) t emperature range: ?5 to 125 c i k = 10 ma out gnd 15 k 8.25 k 9 m f small signal v oltage gain vs. frequency
8 astec semiconductor as432 1.24v precision adjustable shunt reference/amplifier t ypical performance curves figure 12 figure 13 4 3 input and output v otages (v) 2 1 0 ? 0 1 2 3 4 5 6 7 t ?t ime ( m s) 8 9 10 11 12 input output pulse response input monitor 220 w 50 w out gnd f p = 100 khz 100 90 80 70 60 50 40 30 20 10 0 10 0 10 1 10 2 10 3 c l ?load capacitance (pf) 10 4 10 5 10 6 10 7 150 w c l 10 k i k a c d b t a = 25 c stability boundar y conditions stability region i k ?cathode current (ma) a: v ka = v ref b: v ka = 5 v at i k = 10 ma c: v ka = 10 v at i k = 10 ma d: v ka = 15 v at i k = 10 ma
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