An electrical device like this requires a reverse leakage current of 500nA @ 3.5V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 6.8V.For operation, diode reaches 1.1V @ 100mA at the maximum voltage - Forward (Vf).
PDZ6.8B,115 Features
reverse leakage current of 500nA @ 3.5V 500nA @ 3.5V is the maximum voltage (Tol)
PDZ6.8B,115 Applications
There are a lot of Nexperia USA Inc. PDZ6.8B,115 applications of zener single diodes.