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DRV8302 Gate drive limitations

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nickw1881
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DRV8302 Gate drive limitations

Do we know what the limitations are on the DRV8302 gate drive circuit? There is a good discussion about it here:

http://vedder.se/forums/viewtopic.php?t=70

and here:

http://www.electric-skateboard.builders/t/who-is-using-foc-and-whats-you...

It looks like the DRV8302 gate drive power supply blows up if it's pushed too hard. I blew up 3 today :D Same symptoms, red light flashes for fault, GVDD pin on DRV8302 is ~1V. VESC design has some rather large gate capacitances, we might be "riding the line" as far as the capabilities of this FET driver. This could also be a symptom of some other problem, and GVDD is disabled because of the other problem. Not sure what else it could be though.

I was running on a dyno with 30kHz FOC switching frequency and a 12S/50V battery. The DRVs all gave out a little over 60A motor current at about 25% throttle/duty. No problem up to 60A, and no problem unloaded up to 100% throttle. Why would switching the gates at higher motor loads cause higher switch drive currents? Does that make any sense? The switch gate capacitance doesn't change with the current through the switch does it?

The new VSC 6 has a very similar gate drive circuit, is it susceptible to the same failure modes? Has anyone tried putting a load resistor on the DRV830x GVDD pin to see where it breaks at 12S?