DRV8303: Negative gate voltage during regeneration

Simone Freato

Part Number: DRV8303
Other Parts Discussed in Thread: DRV8301

Hello to everyone,

I have a new issue with the above mentioned three phase driver.

I have an application where I use two legs of drv8303 to drive a reversible DC motor. In this application there's the real chance that this motor will be forced to move while the drive is turned off. Here is what I see on the scope when I move the motor to a fraction of the nominal speed.

Green trace is HS_A

Yellow is GH_A

Pink is GH_A - HS_A

As you can see there's a negative VGH_DIF lower than the minimum absolute rating of the IC. And, of course, sometimes the IC is killed by this treatment.

I can't find any workaround, since it seems to me that vbus capacitors charging through the body diode of the high side mosfet is causing the presence of this voltage. Does it means i can't use DRV8303 in an application where i can expect some kind of regeneration into a turned off board?

over 6 years ago

0 Rick Duncan over 6 years ago

TI__Guru** 114905 points

Hi Simone,

We will investigate and reply soon.

0 Simone Freato over 6 years ago in reply to Rick Duncan

Prodigy 170 points

Hi Rick,

did you find anything about this matter? Do you need further information?

0 Rick Duncan over 6 years ago in reply to Simone Freato

TI__Guru** 114905 points

Hi Simone,

Sorry for the delay, and thank you for reminding me. I have contacted the experts on this device. We should have a response in a couple of days.

0 Phil Beard over 6 years ago in reply to Rick Duncan

TI__Expert 4650 points

Hi Simone,

Can you clarify what HS_A and GH_A nets correspond to pins on the DRV8303?

0 Simone Freato over 6 years ago in reply to Phil Beard

Prodigy 170 points

I'm sorry, I was meaning SH_A and GH_A, pins 42 and 43.

0 Phil Beard over 6 years ago in reply to Simone Freato

TI__Expert 4650 points

Hi Simone,

Thank you for the information.

This is most likely damaging a diode between the SH_A and GH_A pins inside of our part. Is is possible for you to disconnect the motor in your application from the mechanical system back driving it?

When the motor is acting like a generator, there is not a lot we can do in our system to protect against this continued stress to our part except to electrically or mechanically disconnect the motor.

0 Phil Beard over 6 years ago in reply to Phil Beard

TI__Expert 4650 points

Hi Simone,

Can you take a picture of the top of the device and send it to us? We'd like to make sure this isn't a change we made in silicon causing the part to be damaged.

0 Simone Freato over 6 years ago in reply to Phil Beard

Prodigy 170 points

Hi Phil,

here you are a photo of the IC. Your hypothesis is supported by the fact that this is the first time we see a damage in this condition, we use DRV8301 and DRV8301 since 5 years now, and regeneration with a powered off inverter is quite common in our applications.

Thanks for your support.

0 Phil Beard over 6 years ago in reply to Simone Freato

TI__Expert 4650 points

Hi Simone,

Thank you for the image. Please give me a couple days to close with our design team on whether this part is affected.

0 Simone Freato over 6 years ago in reply to Phil Beard

Prodigy 170 points

Hi Phil,

have you got some news?

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DRV8303: Negative gate voltage during regeneration