H-bridge with 4 n-ch mosfets (
IRF1405) with a gate capacitance of 5480pF and turn on delay time
13nS. I am using a hip4081 as my driver which has a peak current of
3.8A! This is how I am calculating the max pwm frequency my circuit can handle:
(1) R=V/I plug in
(2) => t=(V/I) * C
V=Gate Voltage (10V)
I=Max gate current (3.8A)
C=Input gate capacitance (5480pF)
plugging these values I get
t = 14.4 nS. now this is the time it will take to charge the gate capacitance and so my pwm frequency should be < 1/t?
does this sound right? Please add your insights.
Load is a wheelchair motor
Power = 150 - 450 W Voltage = 24VDC I = P/v = 7A - 19A