This is the PSU from the MC3X60V – my small motor controller. It snapped at 35V. To save space I omitted the components in the yellow circle.

Reviewing this with a friend I believe that C10 is the cause. This circuit need a small cap close to TSP54060. I already know that this circuit misbehaved without the larger motor caps mounted (not shown), so it is something to this, but we will see as I get around to patching a PCB.

The resistors R11 and R12 should be ok according to the datasheet. This set the under-voltage cut off and can be left floating – or more correct that is my interpretation of the datasheet for TPS54060.

I will see if I can patch one of the PCB’s as proof of concept, but I also want to make and order a break out board for a few of the 60ich V designs. As you can see above – the PSU is in the top-left corner and I don’t have much space here either. Also – again I will need to allow 60V components on C10.

Next question – Is this actually a 60V design?

The answer is NO! The circuit say 60V, but if you actually operate a motor controller on marginal design terms you will break it. This is a design for 48V with a max limit of 60V allowing it some tolerance.

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