[C6655] connecting heat sink to ground (VSS) ?

Naoki Kawada

Guru 19890 points

Hi,

My customer applies heat sink to their c6555. They are now wondering if the heat sink should be connected to ground (C6655 VSS plane) or not. Do you have any suggestion for this ? To me, it could be left floating... but not sure it is acceptable or not.

Best Regards,
Naoki

over 7 years ago

0 Senthilkumar Srinivasan over 7 years ago

TI__Mastermind 43660 points

Hello Naoki,

There is no need to connect the heat sink to ground.

Regards,
Senthil

0 Naoki Kawada over 7 years ago in reply to Senthilkumar Srinivasan

Guru 19890 points

Hello Senthil, Thank you for your answer. I will forward this to my customer. Best regards, Naoki

0 Naoki Kawada over 7 years ago in reply to Naoki Kawada

Guru 19890 points

Hi Senthil,

My customer wants to know the reason for the recommendation of no-connect the heat sink to ground. Any comments on this ?

Best Regards,
Naoki

0 Senthilkumar Srinivasan over 7 years ago in reply to Naoki Kawada

TI__Mastermind 43660 points

Naoki,

There is no specific reason for not connecting heat sink to ground. We have heatsink to dissipate the heat generated by the silicon. As far as i know, we do not have any board which have heatsink connected to the ground.

Regards,
Senthil

0 Naoki Kawada over 7 years ago in reply to Senthilkumar Srinivasan

Guru 19890 points

Hi Senthil,

I agree with you about the path of dissipating the heat, but it seems they had just wondered if connecting heat sink to GND might also improve noise immunity on the device as well as improving heat dissipating. To me, I think almost no improvement is expected. What do you think of this ?

Best Regards,
Naoki

0 Senthilkumar Srinivasan over 7 years ago in reply to Naoki Kawada

TI__Mastermind 43660 points

Naoki,

I don't think connecting the heatsink to ground would improve the noise immunity. Heatsink would not be a source for noise.

Regards,
Senthil

0 Naoki Kawada over 7 years ago in reply to Senthilkumar Srinivasan

Guru 19890 points

Senthil,

Sorry for the delayed response. I got a feedback on your comments. They also think heat sink would not be source for noise. They are wondering if the grounded heat sink might work as a 'shield' against the exogenous noise. I believe TI does not intend/verify to use heat sink for such kind of purpose, so it is customer's responsibility to do this, but please let me know if you have any comments from this perspective.

Best Regards
Naoki

0 Senthilkumar Srinivasan over 7 years ago in reply to Naoki Kawada

TI__Mastermind 43660 points

Naoki,

There is no more comment from us. If the customer want to experiment this, its there responsibility to verify this.

Regards,
Senthil

0 Naoki Kawada over 7 years ago in reply to Senthilkumar Srinivasan

Guru 19890 points

Ok, thanks, Senthil. Now I close thread.

Best Regards,
Naoki

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[C6655] connecting heat sink to ground (VSS) ?