DRV8212: Motor driver current sense and ground

Shashank TS

Part Number: DRV8212

I have two questions regarding the schematics I have attached:

1. Is it ok to connect the thermal pad to the current sense resistor and not directly to ground as shown?

2. I have connected the capacitors C15, C16 and C17 to the common ground and not the motor ground as shown, is this, ok?

over 3 years ago

0 Pablo Armet over 3 years ago

TI__Mastermind 37683 points

Hi Shakshank,

Shashank TS said:
1. Is it ok to connect the thermal pad to the current sense resistor and not directly to ground as shown?

If your purpose is current sensing, I do not recommend this. I recommend connecting the sense resistor between device GND and PCB GND. Read section 9.2.4.2 of the datasheet for more information.

Shashank TS said:
2. I have connected the capacitors C15, C16 and C17 to the common ground and not the motor ground as shown, is this, ok?

This is okay. Refer to the EVM schematic above for more reference.

Regards,

Pablo Armet

0 Shashank TS over 3 years ago in reply to Pablo Armet

Prodigy 160 points

Ok. Also are the thermal pad and GND pin of the IC internally shorted? Is the sole purpose of thermal pad only to dissipate heat? So, there is no need to connect the thermal pad to the sense resistor right as shown in my schematic?

0 Pablo Armet over 3 years ago in reply to Shashank TS

TI__Mastermind 37683 points

The Thermal PAD and device GND are not internally connected. This connection has to be manually done in the layout. The way the connection is done in the schematic above is fine to follow.

Regards,

Pablo Armet

0 Shashank TS over 3 years ago in reply to Pablo Armet

Prodigy 160 points

I have changed my schematics based on your initial feedback and reference design you have shared. Can you please confirm this latest schematics block. Also please note that I have used DRV8212 in my design. I have connected the thermal pad to board ground and IC ground through the sense resistor.

Note: R28(0E) is DNP in the above design.

Regards,

Shashank

+1 Pablo Armet over 3 years ago in reply to Shashank TS

TI__Mastermind 37683 points

Shashank,

The VM capacitors need to be connected to PCB GND. If R28 is DNP, C15, C16, and C17 will be floating. Other than that, the rest of the schematic looks good.

Regards,

Pablo

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DRV8212: Motor driver current sense and ground