POWER/GOURND PAD number selection

[tavidu]

how many sso(4mA driving) pads can 1 P/G support
how many sso(8mA driving) pads can 1 P/G support
how many sso(12mA driving) pads can 1 P/G support

process: .13 generic TSMC process

 

[tavidu]

Nobody can give me any suggestion?
I just want assign POWER/GROUD PAD number for my chip.
How many P/G group for core logic about 3,000,000 gate ccount and 4 Mbit SRAM?

Assume for .13 um

 

[hennyjia]

It depends on your package inductance.
You should build a model circuit to choose the number of pad that 1 P/G can support.

Added after 53 minutes:

Using Hspice to get a sso simulation
Assume the customer has given you the package parameters. From the sso simulation result, you can dicide the number.

 

[vikadik]

It all depends on your design, the current needed for your design, also you need to check on ESD designs for your pads

 

[nav_vlsi]

identify the current req for your chip(max value not average), based on this look at power pads that could supply that current, if one pad is unable to meet your req, go for 2 pair of pads.pad selection depends on on your current,current density, wire and cell voltage drop of your design

 

[torlies]

how many sso(4mA driving) pads can 1 P/G support
how many sso(8mA driving) pads can 1 P/G support
how many sso(12mA driving) pads can 1 P/G support

process: .13 generic TSMC process

It depens on your Package inductance, TSMC's datasheet will have a SSO table in the end. It give three option due to your inductance : 5.2nH, 7.2nH, 10.8nH

Use the inductance and driving strength to find data in the SSO lookup table.

 

[shankarmit]

in general for every 6 isignal pads we use one power pad.. you can follow in same way.... it depends on process, voltage....

 

[aravind.b]

go through the document u can get good idea how to calculate the number of ground and power pads

 

[urslen]

I am not able to download the pow_plan.pdf

Is it there still?

 

[funzero]

in gerenal , power/ground pin count will be 1/4 of your total pin count.
and pay attention to p/g location in your pad distribution.

 

[leeenghan]

Hi tavidu,

You should get the answer from the IO pad datasheet you are using.

Regards,
Eng Han