While the device is operating, the maximum voltage - Zener (Nom) is reduced to 3.9V.For operation, diode reaches 1.5V @ 200mA at the maximum voltage - Forward (Vf).
TLZ3V9-GS08 Features
TLZ3V9-GS08 Applications
There are a lot of Vishay Semiconductor Diodes Division TLZ3V9-GS08 applications of zener single diodes.