I am simulating a circuit in ac analysys with ngspice 25.
V(output) give me expected result, as VDB(output).
By the way, TRAN analysys gives the expected result.
But When I plot the phase with VP(output), the vertical ("y") axis is labeled with a "V" (Volt I guess), and this axis gradation are "strange" and do not correspond to nothing I expect.
You can have a look at the plot at : http://lappweb.in2p3.fr/~gaglione/datasheet_ac_phase.pdf
The red curve should be at 180° at low frequency.
Any help or suggestion is welcome !
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
It seems the phase is in radians (180 degrees is PI = 3.14). The 'strange' jump is because there is actually no physical difference between +180 and -180 degrees. (You
appear to want an 'unwrapped' view: use atan2 instead of atan).
In short, the output is correct, but not what you want?
-marcel
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Thank you Marcel !
Indeed, I was not expecting radian but degrees, and did not thought about radians...
I had a look at the manual, but did not succed to use the unwrap function to plot phase in degrees.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Dear ngspice users/developpers,
I am simulating a circuit in ac analysys with ngspice 25.
V(output) give me expected result, as VDB(output).
By the way, TRAN analysys gives the expected result.
But When I plot the phase with VP(output), the vertical ("y") axis is labeled with a "V" (Volt I guess), and this axis gradation are "strange" and do not correspond to nothing I expect.
You can have a look at the plot at : http://lappweb.in2p3.fr/~gaglione/datasheet_ac_phase.pdf
The red curve should be at 180° at low frequency.
Any help or suggestion is welcome !
It seems the phase is in radians (180 degrees is PI = 3.14). The 'strange' jump is because there is actually no physical difference between +180 and -180 degrees. (You
appear to want an 'unwrapped' view: use atan2 instead of atan).
In short, the output is correct, but not what you want?
-marcel
Thank you Marcel !
Indeed, I was not expecting radian but degrees, and did not thought about radians...
I had a look at the manual, but did not succed to use the unwrap function to plot phase in degrees.
Solved !
I add "set units=degrees" and now, I get what I want.
Thank you again.