TPS56637: Recommended Via diameter for on-pad via(GND)

Takashi Onawa

Part Number: TPS56637

Hi Team,

Could you tell me the recommended Via diameter for on-pad via(GND)?

If possible, my customer doesn't want to put on-pad via due to PCB rule in their company, so they want to move it to outside of under device.
Could you tell me the side effect by the layout changes from TI recommendation as well?

Regards,

Takashi Onawa

over 5 years ago

0 Gerold Dhanabalan - High Performance Radar over 5 years ago

TI__Genius 14455 points

Hi Takashi-san

The vias on the PGND pad are thermal vias and they help improve the thermals. We recommend having the thermal vias. Moving them away can degrade the thermal performance.

Regards,

Gerold

0 Yuchang Zhang over 5 years ago in reply to Gerold Dhanabalan - High Performance Radar

TI__Mastermind 18510 points

Takashi-san,

The function of these vias is explained by Gerold, if this is limited by SMT process, recommend to add some vias at copper plane close to the PGND pin like below.

Yuchang

0 Takashi Onawa over 5 years ago in reply to Yuchang Zhang

TI__Genius 13200 points

Hi Gerold-san, Yuchang-san,

Thanks for your prompt response on this. OK, I understood the meaning of the Vias.

Could you tell me the hall diameter of the Vias which used in our EVM as well?
If it's hall size is acceptable for their PCB bender, they can use Yuchang's suggestion.

Regards,

Takashi Onawa

0 Yuchang Zhang over 5 years ago in reply to Takashi Onawa

TI__Mastermind 18510 points

Takashi-san,

2010 size is used for EVM, and if there is DRC rule limited, try to use 3~4 pcs 1608 size instead.

Yuchang

0 Takashi Onawa over 5 years ago in reply to Yuchang Zhang

TI__Genius 13200 points

Hi Yuchang-san,

Sorry, I didn't make sure "2010" and "1608" means.
Could you supplement the meaning of the code?

Regards,

Takashi Onawa

0 Yuchang Zhang over 5 years ago in reply to Takashi Onawa

TI__Mastermind 18510 points

Takashi-san, 20/16 is the external ring size of the via with "mil" unit, 10/08 is the inner size of the via.

Yuchang

0 Takashi Onawa over 5 years ago in reply to Yuchang Zhang

TI__Genius 13200 points

Hi Yuchang-san,

Thanks, I understood.

Regards,

Takashi Onawa

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TPS56637: Recommended Via diameter for on-pad via(GND)