Hi guys,
What's the best way to get rms vdd pote...

# sky130h

Hugo Dias

01/31/2023, 11:57 AMHi guys,
What's the best way to get rms vdd potency (Real and Aparent)?
I did:
let pot= - i(vdd) *vd
meas tran pot_rms rms pot from... (or something like that)
Obs. : it worked, but i dont know if its the more safe way.
Obs. 2: i dont know if i got a Apparent or Real potency with that code shown.

s

Stefan Schippers

01/31/2023, 2:01 PMYou are in the time domain. Do not calculate the **power**.
RMS is the (square root) average of squared values, taking the square
of instantaneous power and taking the average is nonsense.
If you want to get the average power do:
**average** power into the capacitor is **zero**. See example below. Instantaneous power into or out a capacitor is apparent, it has net value zero.
See ngspice calculated value (in blue) at the bottom.

`rms`

value of a `let pow = i(v1) * v(a,b)`

`meas tran cap_avg_pow avg pow from=600u to=800u`

If `a`

and `b`

are the nodes of a capacitor and `i(v1)`

is the current flowing into the capacitor in steady state the Stefan Schippers

01/31/2023, 2:02 PM1.png

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