Resistor value when using a PNP to switch 24v from 5v NPN and Schmitt trigger

Irving

Joined Jan 30, 2016
3,885
With MOSFETs, you don't have to worry so much about leakage currents. You do have to be careful of ESD. I have some 2N7000 that now have high leakage current due to ESD events; and I was trying to handle them properly.
True to some extent, but the 2N7000 is an old design. Modern TrenchFET and HexFET designs are far more resistant to ESD with internal zeners & clamping diodes and devices capable of handling amps rather than mA more so.

The main benefit of MOSFETs in switching circuits is that the transition between on and off is more tightly defined & easily acheived than the current driven BJT.

I'm only switching 25mA max though.
The main point is that MOSFETs are more effective and energy efficient switches than BJT. I know that's irrelevant here (but for the record the MOSFET 'on' losses are 50uW v 2.5mW for the BJT @25mA and 20mW v 150mW @ 0.5A) and all the fuss about resistor values and leakage currents goes away with a MOSFET solution.
 
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