An electrical device such as this requires reverse leakage current of 2μA @ 1.5V.During operation, the maximum voltage - Zener (Nom) is reduced to 5.1V volts.
FDZT40RB5.1 Features
reverse leakage current of 2μA @ 1.5V 2μA @ 1.5V is the maximum voltage (Tol)
FDZT40RB5.1 Applications
There are a lot of ROHM Semiconductor FDZT40RB5.1 applications of zener single diodes.