An electrical device like this requires a reverse leakage current of 5μA @ 1V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 4.3V.
ACZRM5229B-HF Features
reverse leakage current of 5μA @ 1V 5μA @ 1V is the maximum voltage (Tol)
ACZRM5229B-HF Applications
There are a lot of Comchip Technology ACZRM5229B-HF applications of zener single diodes.