An electrical device like this requires a reverse leakage current of 3μA @ 2V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 4.7V.For operation, diode reaches 900mV @ 10mA at the maximum voltage - Forward (Vf).
BZT52-B4V7J Features
reverse leakage current of 3μA @ 2V 3μA @ 2V is the maximum voltage (Tol)
BZT52-B4V7J Applications
There are a lot of Nexperia USA Inc. BZT52-B4V7J applications of zener single diodes.