Offset voltage issues when extracting parameters using Calibre PEX

[benwgl]

I use calibre PEX extracting parasitic paramerter including resister and capacitor,
But OTA bias voltage have 100mv offset when using hspice simulating it. The OTA is cmos circuits. Bias voltage drives the gate of mos. Please tell me why.

 

[tsanlee]

calibre PEX

Can you paste the detail circuit.

The offest voltage maybe come form another sub-circuit (input stage ,feedback,or systematic offset..)