I know there are fancy h-bridge ic's to drive high side of h-bridge but I guess that is when I have to drive n channel mosfet.
I am planning on using p channel mosfets on high side and n channel ttl mosfets on low side. I will driving the high side with n channel mosfets.
My Vbatt
is 12 V and I will be controlling a wheelchair motor which can conduct upto 30A
under load.
my concerns:
1. How do I calculate gate drive current for the p-mos since the gate capacitance has to be fully charged for maximum Id
? do I just use i=Q/t
, where t is charge time and Q is gate charge. But how does the pwm frequency come into play? say if i am using 31khz
2. How can I calculate the values of the resistors (connected from Vbatt
to Gate of n-mos)
3. Do I have to worry about gate resistors?
Shoot through won't be a problem since I will put a delay when switching direction. Any help would greatly be appreciated.