5% indicates the maximum possible voltage (Tol) of 5%.While operating, the maximum voltage - Zener (Nom) is reduced to 19.2VV.As the voltage (Temp Coeff) reaches its maximum value, it reaches 0.192mV/°C.
1N4928A Features
1N4928A Applications
There are a lot of Microsemi Corporation 1N4928A applications of zener single diodes.