Need help with BLDC Controller PCB Layout

[HacknMod]

Thanks for the input Hardym and Jeremy!

You have the shunt in there but no circuitry to shown to convert it to something useful.

The isense is going to the brain board where it's being inputted into the MC33033. I copied this from Jeremy's schematic. See an image of my the MC33033's configuration on my brain board here: http://i.imgur.com/Tb1nD.png - Will this work?

Fortunately I was able to find this on the bench, and fixed with a couple of .01 caps at the inputs. I see that you've used .001 which would probably also be ok.

Would it be "better" to use .01?

[hardym]

The isense is going to the brain board where it's being inputted into the MC33033. I copied this from Jeremy's schematic. See an image of my the MC33033's configuration on my brain board here: http://i.imgur.com/Tb1nD.png - Will this work?

Probably. I've not used the MC33033, but I think Jeremy had some success. This is a very basic chip without regen, so your current sense may work.

Would it be "better" to use .01?

I dont know, but it probably wont hurt. I was responding to your PM, and tyring to apply a few lessons learned from my old project, to your reported NCP5181 failures, so it's just a guess. I didn't have the same types of failures that you are having, so I'm not sure of the problem.

[Jeremy Harris]

Current sense on the MC33033 is excellent, far, far, faster than on ebike controllers. It does cycle-by-cycle limiting on each pwm pulse, as it uses a comparator on the sense input, not a voltage amplifier. If the sense input goes over 100 mV, then the controller terminates the pulse. This is why there is some simple filtering on the sense connection, to take out narrow noise spikes. Because of the cycle-by-cycle limiting, a bit of noise tends not to be too big a problem, as most of the electrical noise comes from the phase surrent being turned off, the event that is triggered on over-current by the current limit comparator.