Number of ground pads used in a design

[tweethy]

Why is it that nof ground pads used in a design are roughly 10% more than the nof power pads?

 

[lohi21]

To have better sinking advantage. and to reduce the path completion resistance, else u might have end up having huge ground bounce

 

[sputty6]

Hi lohi21

Could you please explain me how does ground bounce effect decrease if we increase the number of ground pads??? Also what do u mean by better sinking advantage????

Thanks

 

[lohi21]

Hi sputty6,

The attachments will give you more information of multiple P/G pads in the design.

Hope this helps.

 

[nav_vlsi]

Also lot of time, if we have isolated power supplies in design , we would have different POWER (VDD) domains, but still we might share the same ground network. hence the need for VSS pads would arise in those scenarios.