When to use MOSFET protection diode?

[spargo]

I understand some MOSFETs do not have internal protection diodes and it is recommended to add one externally.  Is this necessary if you're already including something like a 1N4001 reversed to ground in your power filtering section?

Does anyone have a list of common MOSFETs that do/don't have internal protection diodes?

[R.G.]

I understand some MOSFETs do not have internal protection diodes and it is recommended to add one externally.  Is this necessary if you're already including something like a 1N4001 reversed to ground in your power filtering section?

Yes, it is. It's the gate to source voltage you're trying to control. The polarity and size of the source to drain voltage is relatively unimportant for this. The slam-dunk solution is to use a 10V-12V zener with cathode to gate, anode to source.

Does anyone have a list of common MOSFETs that do/don't have internal protection diodes?

Probably. But wouldn't it be simpler to find what MOSFETs  you can get or want to get, and then google their datasheets, which will show this? That will take about 10 seconds per device.