false phase in AC analysis

Status
Not open for further replies.
G

gevy

Full Member level 6
Joined
Nov 17, 2004
Messages
340
Helped
60
Reputation
120
Reaction score
29
Trophy points
1,308
Location
Russia
Activity points
2,167
I simulate AC analysis of Op Amp by using of Spectre (Cadence).
Sometimes false 180° is added or subtracted to phase characteristic.
How I can to remove this error ?
 

Do you mean when the phase is increased or decreased to some extent, there is be a 180 substracted or added? This is normal for the display.
If it is not this case ,then it may be a bug for the tool.
 

gevy said:
I simulate AC analysis of Op Amp by using of Spectre (Cadence).
Sometimes false 180° is added or subtracted to phase characteristic.
How I can to remove this error ?
Click to expand...

Are you sure that you probe the right node, for example, probe the positive input
and positive output?or positive input and negative output?
 

I measure phase between noninverting input and output of Op Amp.
Sometimes false 180° is added or subtracted to phase characteristic near zero frequency ! It is error of simulation. I am sure that zero frequency phase is zero.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…