The TLV431 series of parts are precision low voltage shunt regulators that are programmable over a wide voltage range of 1.24V to 16V. The TLV431A series features a guaranteed reference accuracy of 1.0% at 25 °C and 2.0% over the entire industrial temperature range of -40 °C to 85 °C. For TLV431B series, the accuracy is 0.5% and 1.0%, respectively. For the TLV431C series, the accuracy is 0.2% and 0.5%, respectively. These devices exhibit a sharp low current turn-on characteristic with a low dynamic impedance of 0.20Wover an operating current range of 0.1mA to 20mA. This combination of features makes this series an excellent replacement for zener diodes in numerous applications circuits that require a precise refrence voltage. When combined with an optocoupler, the TLV431 can be used as an error amplifier for controlling the feedback loop in isolated low output voltage (3.0V to 3.3V) switching power supplies. These devices are available in economical TO-92 and micro size TSOP-5 and SOT23-3 packages.