I'm building a class D amplifier with a dsPIC as PWM modulator.
The part of the schematic that I want to talk about is the interaction between the microcontroller output (pwm signal) and the gate of the MOSFET. I use TC4420 and TC4429 as gate drivers.
I know that there could be some overshooting (I think it's called "ringing") every time the output of the driver switches (for the resonant circuit created from gate capacitance and parasitic inductance), but I can see a lot of overshooting even between the output of the microcontroller and the input of the driver that has high impedance!!! Is it normal or am I missing something?? If it's normal, is it true that that overshooting can be lowered only with a series resistor?
Talking about switching in the same pcb of a class D amp, is it true that is recomended to have two separate grounds for logic signals and for power? I searched the internet but I don't get this point: how can i have two separate grounds if the power cables has only one ground wire?