An electrical device like this requires a reverse leakage current of 2μA @ 3V.While the device is operating, the maximum voltage - Zener (Nom) is reduced to 6.4V.
JAN1N4581AUR-1 Features
reverse leakage current of 2μA @ 3V 2μA @ 3V is the maximum voltage (Tol)
JAN1N4581AUR-1 Applications
There are a lot of Microsemi Corporation JAN1N4581AUR-1 applications of zener single diodes.