frozenduck
Newbie level 4
Hi all,
I found when running spectre turbo for DC analysis in some circumstance (ex. low supply voltage, low temperature or transistor corners), it gives different DC operating point compared to spectre w/o turbo enabled. I think the results calculated by spectre turbo is wrong because if I just increase the temperature or voltage a little bit (even 0.1 degree), the results between spectre with and without turbo enabled are the same.
The circuit is an OTA with CMFB simulated in closed-loop configuration. Wrong DC operating points usually show the output common voltages saturate to supply voltage.
I tried to tighten the reltol but there were no differences between results. Is there any possible reason causing these wrong simulation results? How to fix it? Thanks.
p.s. the simulator is MMSIM72
I found when running spectre turbo for DC analysis in some circumstance (ex. low supply voltage, low temperature or transistor corners), it gives different DC operating point compared to spectre w/o turbo enabled. I think the results calculated by spectre turbo is wrong because if I just increase the temperature or voltage a little bit (even 0.1 degree), the results between spectre with and without turbo enabled are the same.
The circuit is an OTA with CMFB simulated in closed-loop configuration. Wrong DC operating points usually show the output common voltages saturate to supply voltage.
I tried to tighten the reltol but there were no differences between results. Is there any possible reason causing these wrong simulation results? How to fix it? Thanks.
p.s. the simulator is MMSIM72