What is the difference between a H-bridge DC motor driver with N-Channel mosfet and a H-bridge DC motor driver with N-Channel and P-channel mosfet?
Which one is better?
Dear Nader
Hi
It is simple , the driver with just Nmosfets will be better , because of similarity between your mosfets , and identical dissipations . and at higher frequencies , we can't use p mosfet and n mosfet in a circuit simply , because of overlap problem but with nmosfets , the dead time creation will be easier .
Best Wishes
Goldsmith
the N-channel upper mosfets requires a bootstrap circuitry to effectively drive the MOSFETs.......the RDSon of N-MOS is very less compared to P-MOS......
The upper two MOSFETs are configured as high-side switches.
For N-channel MOSFETs, high-side driving is somewhat of a hassle if you don't know about it.
You can turn the high-side P-channel MOSFET on by simply pull the gate to ground (in the circuit shown, where the voltage is 9V).
To turn the high-side N-channel MOSFET on, you need to provide approximately (9+8=)17V. So, you need to either use a charge pump circuit, a gate drive transformer or a high-side driver.
So, it's easier to turn the high-side P-channel MOSFET on/off. However, at higher voltages and currents, it may be more desirable to use N-channel MOSFETs due to lower on-resistances and thus lower losses and greater efficiency. Also, at higher voltages (usually > 20V, but sometimes 30V - the max VGS of the P-channel MOSFET), you can't turn it on simply by grounding the gate. Then, you need level-shifting circuitry.
You can read about high-side driving for N-channel MOSFETs here, where I've explained it a little: