I'm using the freeware version of SIMetrix. Recomended by Rod Elliot. It has a virtual Bode analysis instrument. What the freeware version does not have is full documentation.
What I'm trying to see is phase vs. frequency as it affects the NFB return. I've assumed that the correct way to connenct this instument in the SIM is one pin connected to the the base of the input transistor on differential input sectionr and the other pin to the base of the other transistor where the NFB return meets it. Then I run an AC sweep. The analysis produces two curves one"phase" the other "Gain".
I tried this on Rod's P3A and get a result that looks sensible, namely, as the phase moves beyond 100 deg the gain falls and even becomes negative.
My question: An I using this feature correctly and am I interpreting the results correctly?
What I'm trying to see is phase vs. frequency as it affects the NFB return. I've assumed that the correct way to connenct this instument in the SIM is one pin connected to the the base of the input transistor on differential input sectionr and the other pin to the base of the other transistor where the NFB return meets it. Then I run an AC sweep. The analysis produces two curves one"phase" the other "Gain".
I tried this on Rod's P3A and get a result that looks sensible, namely, as the phase moves beyond 100 deg the gain falls and even becomes negative.
My question: An I using this feature correctly and am I interpreting the results correctly?