DRV8301: Buck shut down during testing

Binil Sabu

Part Number: DRV8301

Hi,

W e are using DRV8301 for our motor controller. We configured buck for MCU supply which is 5V. While testing the controller we have observed that the buck output drops above 155ARMS (phase current). 5V drops to 1.44 which causes the MCU to shutdown and current drops to zero. Then buck voltage rises again which causes the MCU to power back up. As per the datasheet, Buck and driver sections should not share any signals. The change in phase current should not affect buck at all. Anything below 150ARMS is not an issue. Please help. The scope of phase current and VDD_5V is given below. Blue is phase current and red is buck output

over 4 years ago

0 Binil Sabu over 4 years ago

Intellectual 270 points

0 Matt Hein over 4 years ago in reply to Binil Sabu

TI__Mastermind 21805 points

Hello Binil,

Can we see your schematic and layout?

Normally we see that high current reveals improper ground paths or supply drop-outs which result in regulator malfunction. Even though the buck regulator in the DRV8301 does not share any signals with the gate driver, it does share a supply and ground.

Can you measure the voltage at PVDD2, VSENSE, and the DRV8301 power pad (GND) as you run this experiment to see if any of these voltages are dropping out?

Thanks,

Matt

0 Cole Macias over 4 years ago in reply to Binil Sabu

TI__Mastermind 18900 points

Hey Binil Sabu,

Do you need any more help here or can we close this thread?

Best,

-Cole

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DRV8301: Buck shut down during testing