DRV8320: leakage issue

Cherry Zhou

Part Number: DRV8320

Hi Team,

The motor has leakage problems, with very large spurs at the drive end and erratic spurs, causing the motor to spin abnormally.

(The Chinese in above figure is, "PCB copper thickness is 1 oz., temperature rise is 20 degrees, bus outer wire is wider than 149 mils, drain of MOSFET should increase copper area as much as possible to increase the heat dissipation of the MOSFET. The DRV8320HRTV uses GND copper to spread the heat. ")

Could you help check is there anything need to be modified? Thanks.

Best Regards,

Cherry

over 1 year ago

0 Eli Sorenti-Burns over 1 year ago

TI__Intellectual 1350 points

Hi Cherry,

Thank you for the question. How many amps is the customer pushing through the FETs? Can they send a layout too? My theory is this may be caused by inductive coupling.

Best,

Eli

0 FAZHI LIU over 1 year ago in reply to Eli Sorenti-Burns

Prodigy 20 points

0 Cherry Zhou over 1 year ago in reply to FAZHI LIU

TI__Mastermind 22235 points

Hi Eli,

Thank you for the support.

Fazhi is the customer who has raised the issue both on E2E and E2ECHINA, and we could keep discuss the issue here, please let me know if any questions.

Thanks and regards,

Cherry

0 Eli Sorenti-Burns over 1 year ago in reply to Cherry Zhou

TI__Intellectual 1350 points

Hi Cherry, Fazhi,

Thank you for the clarification and the layout!

Cherry Zhou said:
we could keep discuss the issue here,

Please close the other thread so there is no confusion on my end.

Cherry Zhou said:
very large spurs at the drive end and erratic spurs, causing the motor to spin abnormally

Are these spikes just on one motor connection or are all three experiencing voltage spikes? Where is EC2 in the layout? It should be placed close to the MOSFETs. What is the current passing through the MOSFETs? What is the customer's IDRIVE? Higher IDRIVE leads to higher switching speeds which can at times cause spiking. Potentially lowering the IDRIVE or adding a 10 Ohm resistor to the GLx/GHx pins (if the IDRIVE is at its lowest) could solve this issue. Let me know if this helps.

Best,

Eli

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DRV8320: leakage issue