Local and Global variable in Monte Carlo simulation

[mamadmn]

Hi,
What are the exact parameters of Global and Local variable in Monte Carlo simulation?

Thank you

 

[erikl]

In MC context I just know of global and local variation parameters. Local variation parameters refer to variations between the same devices (or circuits) on the same wafer, whereas global variation parameters refer to those variations over several wafers, even several lots of wafers.

 

[mamadmn]

Hi erikl,
You are always helpful, thank you
Would you please introduce a reference or book?
As I found local is for mismatch like differential pairs, but I run a MC in two conditions, one with linking two differential pair and the other without linking. Surprisingly, the results was the same. Did you have a such experience?
I'm a beginner and I''m not familiar with many things.....

 

[erikl]

Would you please introduce a reference or book?

Several times I've already inserted/linked a Cadence Monte Carlo Simulation Tutorial in this forum. Just use the search function!

... I run a MC in two conditions, one with linking two differential pair and the other without linking. Surprisingly, the results was the same. Did you have a such experience?

The netlist doesn't supply any info about the mutual geometrical position of a differential pair (if common centroid, interdigitated, or not even adjacent). So MC analysis cannot differentiate between such cases - how should it? It just will show you various possible differences (of gate voltages or drain currents) based on local or global variation parameters.