|June 15, 2019
|June 16, 2019
|driver mosfet pwm
Driver for IRF540 MOSFET that permits fast PWM of 12V load (LED strip) via 3.3V PWM control signal. Hopefully.
The general idea is that the totem pole configuration allows switching of a 12V signal with a 3.3V control input. Then the PNP/NPN transistor pair ensure fast pullup/pushdown of gate voltage based on that signal.
Without the totem pole layout the active pullup/pushdown pair would get a max base voltage of 3.3V which won't suffice when there's 12V on the other side.
Next I plan to see whether I can simplify it with a 555 timer IC.
A sensible person would've used an off-the-shelf PWM-capable MOSFET driver IC.
I'm just learning but I studied your circuit and I believe Q14, Q15, Q16 will exceed their gate voltages. If you can spare some +3.3v or +5v to that half of the circuit I think you'll have a good circuit.
December 16, 2020
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