I want to do AC analysis and transient analysis for an analog cicuit. I'm facing a problem for my source parameters. I can find two AC sources. In the menu "place"--> "PSpice component"-->"Source"-->"voltage sources". There I have "AC" and "Sine"
Now, for the "Sine" source, I can set 4 parameters.
- VOFF for the offest i figured
- FREQ for the frequency
- VAMPL and AC. And I don't know what these are for and the difference between the two.
The second source is "AC" and here i can parameter the "Vac" and "Vdc" which must be the DC votltage and AC voltage. I'm guessing that this source is for AC sweep simulations.
I'm using Cadence Allegro Entry CIS 17.2-2016
Thanx for your help!
AMPL(itude) for Transient Analysis, AC for AC Sweep, Simulations. (So that you don't have to change sources for different Analysis Types)
Thank you for your answer!
So in my case I set both VAMPL and AC at the same value?
You can but, by convention, the AC value should be 1(V pk-pk) then the results in dB will "drop out"
Ah... that's an issue. I'm working on very low signals that I want to amplify in an Opamp. 30 to 50 µV.
You can use the "low" values for the Transient Analysis, the AC Sweep takes the equivalent circuit at the Bias Point before the frequency sweep is run, using a value of 1 (V pk-pk) for the AC magnitude is typical since "clipping" isn't a factor.