Programmable
Precision References
The TL431, A, B 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 Vref to 36 V with two external resistors. These
devices exhibit a wide operating current range of 1.0 mA to 100 mA
with a typical dynamic impedance of 0.22 W. The characteristics of
these references make them excellent replacements for zener diodes in
many applications 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 TL431, A, B
operates as a shunt regulator, it can be used as either a positive or
negative voltage reference.


? Low Dynamic Output Impedance, 0.22 W Typical
? Sink Current Capability of 1.0 mA to 100 mA
? Equivalent Full–Range Temperature Coefficient of 50 ppm/°C