An electrical device like this requires a reverse leakage current of 50nA @ 32.9V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 47V.For operation, diode reaches 900mV @ 10mA at the maximum voltage - Forward (Vf).
BZT52-B47X Features
reverse leakage current of 50nA @ 32.9V 50nA @ 32.9V is the maximum voltage (Tol)
BZT52-B47X Applications
There are a lot of Nexperia USA Inc. BZT52-B47X applications of zener single diodes.