Power consumption in Cadence

[baseball07]

Hi everyone. I was wondering what the best way to calculate the power consumption of a circuit designed in Cadence is. In my circuit, VDD is 3V. Once I run the simulation, I do a DC analysis of the circuit then go to results-->annotate-->DC operating points. This shows the current flowing through the power supply for the circuit. Do I simply multiply this by 3V to get the total power consumed? Should I be doing some sort of transient analysis for power consumption or is DC ok?

 

[JoannesPaulus]

I'd run a transient simulation and then the average of the current from your voltage source and multiply by 3V.

 

[love_analog]

Also make sure your circuit has settled to the correct mode before measuring power. This is true for transient circuits eg. say you have ac coupling cap.
not an issue with Dc circuits where nothing is toggling.

 

[AdvaRes]

I'd run a transient simulation and then the average of the current from your voltage source and multiply by 3V.

Hi all,
@JoannesPaulus,
Your technique let measure only the average of the total power consumed by the circuit. Do you know an idea letting separate this total power in dynamic power and static power ?

 

[JoannesPaulus]

I never tried to separate them... what about:

rms(IT("/V0/PLUS")-average(IT("/V0/PLUS")))

i.e. the dynamic power is the rms of the total current minus its average value.
I am not sure this is correct... Any other ideas?

 

[AdvaRes]

I never tried to separate them... what about:

rms(IT("/V0/PLUS")-average(IT("/V0/PLUS")))

i.e. the dynamic power is the rms of the total current minus its average value.
I am not sure this is correct... Any other ideas?

Euh, no JoannesPaulus we can't separate them that way.

 

[JoannesPaulus]

I tried a few different cases and figured out that the formula I wrote in my previous post is incorrect: a dynamic signal can still have an average current... I do not think you can really separate dynamic and static power.

 

[AdvaRes]

OK thanks.
Did you use Spectre or Eldo ?