DRV8832: find damage reason

Holly Hong

Intellectual 1850 points

Part Number: DRV8832

DRV8832 occasionally damaged after working for a period of time. damaged part is shorted between VCC and GND.

now we have no idea why this happened

below is the schematic:

and below is the test result of OUT1/2. the two pictures are the same because the second one cannot see the clear axis.

over 3 years ago

0 Wang5577 over 3 years ago

TI__Guru 56650 points

Holly,

Where is the VCC connected to?

Regards,
Wang Li

0 Holly Hong over 3 years ago in reply to Wang5577

TI__Intellectual 1850 points

you can refer to this picture

0 Wang5577 over 3 years ago in reply to Holly Hong

TI__Guru 56650 points

Hello, Holly,

The picture resolution is too low. I cannot read out the VCC connection. I guess the VCC doesn't have enough capacitance.

Regards,

Wang Li

0 Holly Hong over 3 years ago in reply to Wang5577

TI__Intellectual 1850 points

0 Holly Hong over 3 years ago in reply to Wang5577

TI__Intellectual 1850 points

VCC doesn't have enough capacitance can cause part damaged?

0 Wang5577 over 3 years ago in reply to Holly Hong

TI__Guru 56650 points

Holly,

Possible if a large motor winding current is sent back to VCC.

Would you share the VCC, OUT1 and OUT2 voltage? BTW, on the previous waveform, I cannot read out the peak current.

Regards,

Wang

0 Holly Hong over 3 years ago in reply to Wang5577

TI__Intellectual 1850 points

customer also think this is the reason.

could you please help solve this issue?

below is the out waveform, you can zoom out the picture to see clearly. horizontal axis unit is s; vertical axis unit is mA.

0 Ryan Kehr over 3 years ago in reply to Holly Hong

TI__Guru 55605 points

Hello,

Wang is referring to this blog to describe "supply pumping".

https://e2e.ti.com/blogs_/b/industrial_strength/posts/art-of-stopping-the-motor-vm-pumping

As Wang requested, what is the VCC voltage under normal operation? Can they check VCC voltage during operation?

Regards,

Ryan

0 Holly Hong over 3 years ago in reply to Ryan Kehr

TI__Intellectual 1850 points

VVC voltage is about 4.5~6V

+1 Wang5577 over 3 years ago in reply to Holly Hong

TI__Guru 56650 points

Ryan,

Thanks,

Holly,

I would think 4.5~6V VCC is normal voltage range which cannot cause the damage. But, if a large energy is sent back from the motor, it can push the input higher than 7V.

Please check that blog article to "Reduce VM pumping". Or, you can put a TVS diode on VCC to protect the device.

Regards,

Wang Li

Motor drivers

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DRV8832: find damage reason