I'm controlling a P-Ch MOSFET on a circuit,
- VIN is 8-30V
- TTL_IN is a 0-5V signal generated by a MCU, which can source/sink currents up to 15mA
- Zener Izt 5mA (BZT52C15)
- MOSFET Vgs limit 25V
I'm currently using this circuit:
I find many different implementations for this situation; I see voltage dividers at gate, emitter resistors for current limiting, replace NPN with a small N-ch FET, gate driver IC's etc.
My questions are:
- Is my circuit is valid and safely usable? (I actually use it with no obvious effects (heating etc.) but I want to be sure)
- For relatively fast (5KHz) switching speeds, what should I need to change?
- I previously used 10K for R12 and it cannot charge the gate fast enough, leading slow turn off times. 1k is much better for regarding speed but I'm not sure R9 limits the current enough.