advanced monolithic systems, inc. 6680b sierra lane, dublin, ca 94568 phone (925) 556-9090 fax (925) 556-9140 advanced ams3431 monolithic precision adjustable shunt regulator systems features applications trimmed 0.25% reference battery powered systems wide operating current range 250 m m a to 150ma switching power supplies low dynamic output impedance adjustable power supplies low output noise linear regulators nominal temperature range to 85 c error amplifiers temperature-compensated: 60ppm/ c notebook/personal computer internal amplifier with 150ma capability monitors/ vcr/ tv pagers general description the ams3431 is a three-terminal adjustable shunt regulator with guaranteed temperature stability over the entire range of operation. the output voltage can be set to any value between 2.5v (vref) and 36v by adding two external resistors. due to the sharp turn-on characteristics this device is an excellent replacement for zener diodes in many applications. ams3431 is available in the space saving sot-23 package and in the to-92 package. ordering information: tol. package type operating to-92 3 lead sot-23 temperature range 0.25% AMS3431An AMS3431Am -40 to +85 c 0.5% ams3431bn ams3431bm -40 to +85 c 1.0% ams3431cn ams3431cm -40 to +85 c pin connections to-92 3l sot-23 plastic package (n) (m) 1 2 3 cathode anode ref cathode ref anode bottom view top view
advanced monolithic systems, inc. 6680b sierra lane, dublin, ca 94568 phone (925) 556-9090 fax (925) 556-9140 ams3431 absolute maximum ratings (note 1) cathode voltage (v z ) 37v internal power dissipation (p d ) continuous cathode current (i z ) -10ma to +150ma to-92 package 0.78w reference input current (i ref ) 10ma sot-23 package 0.28w junction temperature (t j ) -40 c to +125 c thermal resistance ( j ja ) storage temperature -65 c to +150 c to-92 package 160 c/w lead temperature (soldering, 10sec.) 265 c sot-23 package 410 c/w note 1: absolute maximum ratings indicate limits beyond which damage to the device may occur. operating ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. for guaranteed specifications and test conditions, see the electrical characteristics . the guaranteed specifications apply only for the test conditions listed. electrical characteristics electrical characteristics at i z =10 ma and t a = +25c unless otherwise specified. parameter conditions AMS3431A min typ max ams3431b min typ max ams3431c min typ max units reference voltage 2.489 2.495 2.501 2.483 2.495 2.507 2.470 2.495 2.520 v deviation of reference input voltage over temperature v z = v ref (circuit 1) t a = +25 c to +85 c t a = -40 c to +25 c 8.0 8.0 15 15 8.0 8.0 15 15 8.0 8.0 15 15 mv mv ratio of change in v z from v ref to 10v -0.5 -2.7 -0.5 -2.7 -0.5 -2.7 mv/v reference voltage to cathode voltage v z from v ref to 36v -1.0 -2.0 -1.0 -2.0 -1.0 -2.0 mv/v reference input current r1 =10k w , r2 = w (test circuit 2) 0.5 4.0 0.5 4.0 0.5 4.0 m a reference input current deviation over temperature r1 =10k w , r2 = w t a = full range (test circuit 2) 0.4 1.2 0.4 1.2 0.4 1.2 m a off state cathode current v z = 36v, v ref = 0v ( test circuit 3) 0.04 0.5 0.04 0.5 0.04 0.5 m a dynamic output impedance f < 1khz, v z = v ref i z =100 m a to 100ma (test circuit 1) 0.25 0.5 0.25 0.5 0.25 0.5 w minimum operating current v z = v ref (test circuit 1) 100 250 100 250 100 250 m a recommended operating conditions: min max cathode voltage, (v z ) v ref 36 v cathode current, (i z ) 0.25ma 120ma
advanced monolithic systems, inc. 6680b sierra lane, dublin, ca 94568 phone (925) 556-9090 fax (925) 556-9140 ams3431 test circuits v in i ref i z v z = v ref v ref v in v z i z v ref i ref r1 r2 v in v z i z off figure 1. test circuit for v z =v ref figure 2. test circuit for v ref vs i z test circuit for i ref . figure 3. test circuit for off-state current typical applications shunt regulator single supply comparator with temperature compensated threshold v+ v ref r2 r1 v o v o ? (1+r1/r2)v ref v on ? 2v v off = v+ v+ out gnd in v th ? 2.5v series regulator higher current shunt regulator v+ r2 r1 v o 0.01 m f 30 w v o ? (1+r1/r2)v ref r1 r1 v o v+ v o ? (1+r1/r2)v ref
advanced monolithic systems, inc. 6680b sierra lane, dublin, ca 94568 phone (925) 556-9090 fax (925) 556-9140 ams3431 typical applications (continued ) over voltage/under voltage protection circuit voltage monitor r1a r2a r1b r2b out on when low < v+ < high limit limit v+ low limit ? v ref ( 1+r1b/r2b)+v be low limit ? v ref ( 1+r1a/r2a) r1a r2a v+ r2b r1b low limit ? v ref ( 1+r1b/r2b)+v be led on when low limit ? v ref ( 1+r1a/r2a) low limit < v + < high limit delay timer current limiter or current source c r on off v+ delay = r*c* l n *v+/(v+)-v ref v+ r cl i o i o =v ref /r cl constant current sink v+ r s i o i o = v ref /r s
advanced monolithic systems, inc. 6680b sierra lane, dublin, ca 94568 phone (925) 556-9090 fax (925) 556-9140 ams3431 typical performance characteristics 0 100 200 300 400 500 0 1.0 2.0 3.0 input current vs v z cathode voltage (v) inputt current ( m a) t a = 25 c v z = v ref 25 70 85 1000 500 125 reference voltage (v) thermal information temperature ( c) 100 0 50 100 150 0 1.0 2.0 3.0 input current vs v z cathode voltage (v) inputt current ( ma) t a = 25 c v z = v ref sot-23 to-92 i z min package dimensions inches (millimeters) unless otherwise noted. 3l to-92 plastic package (n) 0.1400.010 (3.5560.127) 0.0600.010 (1.5240.254) 0.0150.002 (0.3810.051) 0.0160.003 (0.4060.076) 0.0500.005 (1.2700.127) 0.0600.005 (1.5240.127) dia 0.1800.005 (4.5720.127) 0.1800.005 (4.5720.127) 0.050 (1.270) max 0.500 (12.70) min uncontrolled lead dimensions 10 nom 5 nom n (to-92 ) ams drw# 042391 0.90 (2.286) nom
advanced monolithic systems, inc. 6680b sierra lane, dublin, ca 94568 phone (925) 556-9090 fax (925) 556-9140 ams3431 package dimensions inches (millimeters) unless otherwise noted (continued). 3 lead sot-23 plastic package (m) 0.047-0.055 (1.194-1.397) 0.015-0.017 (0.381-0.432) 0.110-0.120 (2.794-3.048) 0.083-0.098 (2.108-2.489) 0.035-0.040 (0.889-1.016) 0.070-0.080 (1.778-2.032) 0.018-0.024 (0.457-0.610) 10 nom 0.0034-0.0050 (0.086-0.127) (sot-23 ) ams drw# 051991 0.035-0.041 (0.089-1.041) 0.0005-0.0040 (0.013-0.102) 0.018-0.024 (0.457-0.610) 10 nom
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