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Simulators >> Circuit Simulators >> Running .spice file in Spectre
https://designers-guide.org/forum/YaBB.pl?num=1473438420

Message started by ValarMorghulis on Sep 9^th, 2016, 9:27am

Title: Running .spice file in Spectre
Post by ValarMorghulis on Sep 9^th, 2016, 9:27am

I am running a .spice file using Spectre simulator of Cadence. I changed the supply voltage value from 1.8V to a different value. However, the output log file shows me similar Total power consumption. I am not sure what am I missing.

Any help would be appreciated.

Thank you.

Title: Re: Running .spice file in Spectre
Post by Geoffrey_Coram on Sep 9^th, 2016, 11:27am

I'm not sure how you expect someone to help you, with the tiny bit of information you've shared -- oh, yes! Spectre doesn't allow any supply voltage except 1.8, so you can't change it! (Kidding.)

There are some circuits that are designed to be insensitive to the supply voltage. Could this be your problem? You haven't told us anything about your circuit.

Are you sure the supply voltage you changed is the main supply? How much did you change it, and how much did the power change?

Is your circuit actually operating? Have you looked at the waveforms to verify this?

Title: Re: Running .spice file in Spectre
Post by ValarMorghulis on Sep 9^th, 2016, 11:36am

Hi,

Thank you for your response. Its actually a power grid benchmark circuit. I changed the Supply from 1.8V to 1.2V to operate in 130nm process. The internal node voltages have been changed. However, the total power calculated by tool didn't change. It remains exactly same. I am assuming there might a global VDD signal that didn't change from 1.8V. But I don't see anything which is still 1.8V in the netlist.

Than you.