The AMS431L is a three-terminal adjustable shunt regulator with guaranteed temperature stability over the entire range of operation. The output voltage can be set to any value between 1.24V (VREF) and 20V by adding two external resistors. The AMS431L features 0.5% initial tolerance, low dynamic output impedance and operates over a wide current range. Due to the sharp turn-on characteristics this device is an excellent replacement for zener diodes in many applications. AMS431 is available in TO-92, SOT-89, 3 pin SOT-23 and 5 pin SOT-23 packages.