An electrical device like this requires a reverse leakage current of 500nA @ 30V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 39V.For operation, diode reaches 1.2V @ 200mA at the maximum voltage - Forward (Vf).
BZG05B39-M3-08 Features
reverse leakage current of 500nA @ 30V 500nA @ 30V is the maximum voltage (Tol)
BZG05B39-M3-08 Applications
There are a lot of Vishay Semiconductor Diodes Division BZG05B39-M3-08 applications of zener single diodes.