The TLV431A, B and C series are precision low voltage shunt regulators that are programmable over a wide voltage range of 1.24 V to 16 V. 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. The TLV431B series features higher reference accuracy of ±0.5% and ±1.0% respectively. For the TLV431C series, the accuracy is even higher. It is ±0.2% and ±1.0% respectively. These devices exhibit a sharp low current turn−on characteristic with a low dynamic impedance of 0.20 over an operating current range of 100 A to 20 mA. This combination of features makes this series an excellent replacement for zener diodes in numerous applications circuits that require a precise reference voltage. When combined with an optocoupler, the TLV431A/B/C can be used as an error amplifier for controlling the feedback loop in isolated low output voltage (3.0 V to 3.3 V) switching power supplies. These devices are available in economical TO−92−3 and micro size TSOP−5 and SOT−23−3 packages.