Raplace high-side MOSFET by P-channel

Hi guys,

I’m planning on building a motordrive that is based on the ODrive. For my application however, using a bootstrap circuit is not allowed. For this reason I consider replacing the high-side n-channel mosfet with a p-channel mosfet and invert the driving signal. The power handled by this motor driver will be very small so the larger Rds of the p-channel MOSFET won’t be an issue. Is there anyone that has any experience with using such an inverter that uses p-channels for the high-side switching. Do you guys think redesigning the odrive in this way is possible? Any thoughts are welcome.

That’s going to have some interesting effects in regards to the body diodes…

Why can’t you use N-channel fets?

I thought about the body diodes but I concluded that this wouldn’t be a problem since the polarity of the body diode in a p-channel MOSFET is the same and the body diode will still be present. What problems do you foresee?

I cannot use N-channels because using a bootstrapping circuit won’t be allowed for my application I cannot have a voltage higher than the supply voltage present in my circuit.

Oh for some reason I thought the body diode was the other way. Yeah should work fine then. Gotta find the right gate driver for it but otherwise no problem.

Good to hear, yeah I thought about which gate driver to use. For the n-channels I wanted to use the UCC27321. For the P-channel I was thinking about using the same driver since the low and high output voltages of this driver should also be able to driver the p-channel MOSFET both on and off. Is this a valid reasoning?