Internal Impedance of sources........

Apos at The Exact Internal Impedance the What values of VDC and IDC of analogLib in the Cadence Virtuoso the Design Environment ...? Please do Enlighten Me in the this Concern ...... Thanks in on Advance .......

vdc default 0
idc default ∞

Thanks a lot for your reply....
But how would they define INFINITE in scripting......?