An electrical device like this requires a reverse leakage current of 5μA @ 4V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 6.2V.For operation, diode reaches 900mV @ 10mA at the maximum voltage - Forward (Vf).
MMBZ5234B_D87Z Features
reverse leakage current of 5μA @ 4V 5μA @ 4V is the maximum voltage (Tol)
MMBZ5234B_D87Z Applications
There are a lot of ON Semiconductor MMBZ5234B_D87Z applications of zener single diodes.