The BZX55B51 is a single Zener diode with a voltage rating of 51V and a power rating of 500mW. It is commonly used in electronic circuits for voltage regulation and protection. The diode has a forward voltage of 1V at a current of 100mA and a reverse leakage current of 100nA at a voltage of 38V. With a tolerance of ±2%, it provides precise voltage regulation. The BZX55B51 is a through-hole diode and comes in a DO-204AH package. It is part of the BZX55 series from Taiwan Semiconductor and is currently active. This diode operates in a temperature range of -55°C to 175°C, making it suitable for a wide range of applications. It is compliant with the REACH regulations and has an ECCN of EAR99.