# Diode - Power Dissipation

1. Dec 16, 2009

### newbieI&E

Question requires a definition and typical values during normal/abnormal operation (Power dissipation of 20A Diode with 1V across it)

Have got definition no problems, but am struggling with typical values.

Power dissipated would be in watts, but in order to provide that you would need either circuit current or resistance of diode (of which I have neither)

Note from tutor specifies reference to Current rating, so am tending to think he wants something about the P.I.V rating, but if so, I don't see how to define that in terms of normal/abnormal operation.

If someone could point me in the right direction would be much apprieciated.

Thanks

2. Dec 16, 2009

### vk6kro

The power dissipated in a diode would be the voltage across it times the current flowing in it.

The voltage is a fairly constant 1 volt for a power diode.

Suppose it was conducting 6 amps, then the power would be (1 volt * 6 amps) = 6 watts.

The 20 amp rating is the maximum current the diode can carry with a suitable heatsink. So, you could work out the power if it was conducting 20 amps.

The peak inverse voltage refers to the maximum voltage that can occur across the diode when it is not conducting. So this would not dissipate any power.