Hello, I am getting ready to do a pcb layout for the h-bridge configuration below which will serve to drive a brushed dc motor. This circuit is for my senior design and i would like to implement best practices to have a fully working circuit. My plan was to have a 4 layer board with a power plane at the top and a ground plane at the bottom and just connect all my low voltage traces in the 2nd and 3rd layer. I have been thinking about adding a bulk capacitor, but i am not sure if that would be necessary. I would appreciate any input, thanks.

 

Why are you not using a H-bridge Gate driver that drives two MOSFETs at a time?
I think an op-amp is not right to drive the bottom MOSFETs.

If the timing is hard, there are Gate Drivers with built in dead time.

I cannot talk about PCB design without knowing what the voltages and currents are.

 

What provision have you made for deadtime in the switching signals? The last thing you want to happen is to have a short across the power supply.

I second @ronsimpson on using an opamp to drive a MOSFET gate. Definitely a suboptimal way to go.

 

100ma is stout for an Op-Amp,
but it's not adequate to switch ~4nf of Gate Capacitance at high speeds.

BTW, a IXFH50N17 doesn't seem to exist, the closest thing seems to be a IXFH50N20,
and your Schematic does not include Voltages,
that Op-Amp drops at least 2-Volts off of the Supply, so keep that in mind.

What are You planning to use for Heat-Sinks ?
Where is the Power-Supply ?, that's one of the most important parts of the Circuit.
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That op-amp is asking for trouble. Look at the datasheet page 14
https://www.ti.com/lit/ds/symlink/lm7171.pdf
and how there is a big peak in the frequency response with capacitive loads over 220pF.
I’m with @ronsimpson and @Papabravo on using a proper gate driver. An op-amp there will cause real problems.