Question

For a Zener diode shunt regulator, the source current is IS, the Zener diode current is IZ and the load current is IL. The source voltage is VS, Zener voltage is VZ and load voltage is VL. The load resistance is RL. What is the correct option for the safe operation of the diode?

(a) IS = IZ + IL

(b) IS =< IZmax + IL

(c) IS =< IZmin + IL

(d) VL = VZ

This question was posed to me in a job interview.

The above asked question is from Voltage Regulators topic in portion Regulators of Analog Circuits

Answer 1

The correct choice is (b) IS =< IZmax + IL

To explain I would say: For proper operation, the current through RS should be at least equal to the sum of IZmin a specified load current. IS >= IZmin + IL

For safe operation of the diode, IS =< IZmax + IL.