DRV8818: After running on power for a few seconds, the motor stopped moving and the MCU may be damaged

zhang ce

Part Number: DRV8818

Tool/software:

After powering on the PCBA, the vref is adjusted to 1.6V and the output current is limited to 2A. After burning the firmware, the FW controls the motor to move continuously, but in reality, the stepper motor stops moving after a few seconds. Moreover, the MCU and driver chip on the PCBA are very hot, and the MCU cannot be burned again. It feels like the MCU is damaged. What may be the possible cause? The MCU power supply is normal.I tried two PCBAs in a row and it's the same problem。

4 months ago

0 Mojtaba Afshar 4 months ago

TI__Expert 4920 points

Hi Zhang,

Thank you for reaching out to us.

Let me review your PCB layout and schematic and get back to you by tomorrow EOD.

Best regards,

Mojtaba.

0 Mojtaba Afshar 4 months ago in reply to Mojtaba Afshar

TI__Expert 4920 points

Hi Zhang,

I have checked the layout I have some questions.

1- Do you use a 2 layer PCB? Would you please provide me each 2-layer layout.

2- How the PPAD is connected to GND? as indicated, it seems that it is connected with a thin trace which leads to over temperature.

Best regards,

Mojtaba.

0 zhang ce 4 months ago in reply to Mojtaba Afshar

Prodigy 20 points

Hi,Mojtaba,

1.I use 4 Layer.

top

gnd

vcc

bottom

2.PPAD is grounded through the gnd layer

thanks

0 Mojtaba Afshar 4 months ago in reply to zhang ce

TI__Expert 4920 points

Hi Zhang,

There should be a hot spot in your PCB which leads to burning the MCU. It seems that the trace connected to PPAD in top layer which is highlighted does not look correct. Please use our EVM hardware design file downloadable from the link below to edit your design.

DRV8818EVM Evaluation board | TI.com

Best regards,

Mojtaba

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DRV8818: After running on power for a few seconds, the motor stopped moving and the MCU may be damaged