Re: How much voltage appears across the zener diode when it is forward bias?

Home Electrical Engineering Forum General Discussion How much voltage appears across the zener diode when it is forward bias? Re: How much voltage appears across the zener diode when it is forward bias?

#12716
Anthony Jarmie
Participant

Hello there,

There will be some resistance in the semiconductor material that causes a voltage to be generated across the device. This voltage is proportional to the current through the diode. Added to this is a voltage, usually less than 1 volt, below which the diode won't conduct in the forward direction. The POWER dissipated in a diode is equal to the voltage across it multiplied by the current through it. So a conducting diode will always get warm. A 5 volt zener will regulate to (obviously) 5 volts, a 25 volt zener to 25 volts. The power rating of the zener is important since considerable power will be dissipated in this type of circuit.

 

Anthony