The RC0431A is a low-voltage 3-terminal adjustable precision voltage reference regulator. It has an excellent thermal stability over the standard commercial temperature range. The output voltage can be set to any value between Vref (1.24V) and 12V using two external resistors. The RC0431A operates from a lower voltage (1.24V) than the traditional shunt regulator references which operate from 2.5V. When used with an optocoupler, the RC0431A will be an ideal voltage reference in an isolated feedback circuit for use in switched-mode power supplies and modular DC-DC converters. The RC0431A has a low output impedance of active output circuitry offering a very sharp turn-on characteristic. The RC0431A will be an excellent replacement for low-voltage zener diodes in many applications such as on-board regulation and adjustable power supplies.