how to do dc mismatch analysis in virtuoso spectre(IC615)

[subbareddy434]

I designed folded cascode opamp for gain of 57db and UGB 16Mhz.i want to to do dcmatch analysis for folded cascode op-amp.when i am doing dcmismatch analysis in spectre it is asking threshold value.I don't know how much value to give .i am using UMC 180nm technology in that i don't know how to include variations in model file for dc mismatch analysis.....
here i am attached a schematic of folded casode op amp..
please help me in this regard...

 

[erikl]

... i want to to do dc mismatch analysis for folded cascode op-amp.when i am doing dcmismatch analysis in spectre it is asking threshold value.I don't know how much value to give .i am using UMC 180nm technology in that i don't know how to include variations in model file for dc mismatch analysis.....

If fabs/foundries provide a Monte Carlo mismatch setup for their process, they usually define either threshold limits or parameter variations with variation type and standard deviation values, s. e.g. slides 11-13 of the MC tutorial below. If you don't have such a setup, just give an estimated threshold value for the offset.

 

[subbareddy434]

thanks for reply should i include mc model file for to do dcmatch analysis...
Here i am attaching the snapshot of mc files which are in my foundry library. could you suggest in which i have to include variations..

 

[monsoon]

Just include the MC model files and define a variable sigma=3 in spectre.

 

[subbareddy434]

thanks for reply..
I am using cadence IC615 and did n't find any option in my spectre window...

 

[monsoon]

In ADE (or ADEXL) there should be a menu "Variables" => Edit. Give the variable name as sigma and value as 3.

 

[subbareddy434]

thanks for reply...
To do mismatch analysis which one i have to use it means whether ADE L or ADEXL
could u give detailedsteps to do mismatch analysis in ADE