ZPY91 is a disc-shaped, glass-passivated, sensitive voltage regulator diode, manufactured by Diotec. It has a breakdown voltage of 91 volts and is able to handle up to 1 ampere of continuous current. The device can be used to provide a low voltage drop when regulating a wide range of input voltages, making it ideal for applications such as switch mode power supplies, battery chargers, and other power protection circuits. The ZPY91 also features low reverse leakage current and has a built in protection to guard against thermal runaway.