The CL2431 is a three terminal adjustable voltage reference designed to act as an open-loop error amplifier with a 2.5V temperature compensated reference. Operating as a low temperature coefficient zener which is programmable from VREF to 18V with two external resistors while providing a wide operating current range of 1.0mA to 100mA with a typical dynamic impedance of 0.15. As a shunt regulator the device can be used as either a positive or negative voltage reference. Active output circuitry provides a very sharp turn-on characteristic, making the CL2431 an excellent replacement for low-voltage zener diodes in many applications, including on-board regulation and adjustable power supplies.