DRV8302: always fault happen

s91240719

Intellectual 340 points

Part Number: DRV8302
Other Parts Discussed in Thread: DRV8301, BOOSTXL-DRV8301

Hi all:

I am using DRV8302 for motor driver.

Our PCB circuit design is follow DRV8301 EVM. But We always get Fault pin feedback .

we already check all function include :

--Buck part design (24V to 3.3V design follow BOOSTXL-DRV8301)

--GVDD cap.

-- Bootstrap cap.

-- charge pump cap.

-- bulid-in OPA setting

--PWM mode,OC mode, OC_ADJ, DC_CAL setting.

When we Pull EN_GATE signal as High state , the Fault pin is active(drive low).

is there any layout issue or some detail we miss?

here is our layout and the DRV8302 PCB circuit as attachment.

Thanks

Andrew

Top + Bottom view

bottom view

3581.DRV8302.PDF

over 6 years ago

0 Rick Duncan over 6 years ago

TI__Guru** 114905 points

Hi Andrew,

Have you checked the AVDD and DVDD voltages?

Is the fault active immediately after EN_GATE is asserted? Does the fault then go inactive?

If it is, you can clear it and ignore the fault. This is a normal power up sequence. As the device is awakened, the regulators are coming up. The last to achieve full voltage is GVDD.

If it is not, please provide details and scope captures of the regulators and nFAULT during EN_GATE toggling from low to high.

0 s91240719 over 6 years ago in reply to Rick Duncan

Intellectual 340 points

Dear Rick:

After check the DRV8302. We found the issue is from the layout.

The path between DRV8302 thermal pad's ground and low side MOSFET's source is too far.

So, jump a wire between thermal pad's ground through hole and MOSFET's Source can solve the issue.

Thank you.

Andrew

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DRV8302: always fault happen