Amplifier Stability & PZ analysis
Amplifier Stability & PZ analysis
(OP)
Hi all,
I was wondering what techniques do you guys use to check the stability of low frequency , very high gain AC coupled amplifier made using Opamps? I ran some simulations for Pole-Zero analysis and the simulator gave output in the form that i never expected....It says "Imag" over Y axis varying from -12.50 to +12.50 and "Real" (rad/sec) over X axis swinging between -3.000T to +3.000T.I expected it to show Gain and phase margins with pole zero location ???.. I don't know what to make of this...anyone?? All my poles and zeros lie exactly at 0 of Y Axis and between 0 to +1.3T (to the right) and this circuit i am so far not able to get it oscillating on board.....I could post a jpg but am unable to find the link on procedure...thanks in advance
I was wondering what techniques do you guys use to check the stability of low frequency , very high gain AC coupled amplifier made using Opamps? I ran some simulations for Pole-Zero analysis and the simulator gave output in the form that i never expected....It says "Imag" over Y axis varying from -12.50 to +12.50 and "Real" (rad/sec) over X axis swinging between -3.000T to +3.000T.I expected it to show Gain and phase margins with pole zero location ???.. I don't know what to make of this...anyone?? All my poles and zeros lie exactly at 0 of Y Axis and between 0 to +1.3T (to the right) and this circuit i am so far not able to get it oscillating on board.....I could post a jpg but am unable to find the link on procedure...thanks in advance





RE: Amplifier Stability & PZ analysis
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Amplifier Stability & PZ analysis
RE: Amplifier Stability & PZ analysis
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Amplifier Stability & PZ analysis
RE: Amplifier Stability & PZ analysis
Here's the link to the screen shots....Yeah Jim, it seems like Giga, Tera but what does such mega units have to do with phase angle, i have no idea....Look up the image and send me your suggestions....Thanks in advance to all who help....
RE: Amplifier Stability & PZ analysis
Are you sure your model component values are what you think?
RE: Amplifier Stability & PZ analysis
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Amplifier Stability & PZ analysis
Fortunately the simulation package i use has facility of defining miliVolt as "mV" and so on. So there is hardly anything that can go wrong there. Moreover , i am getting perfect outputs for Output waveforms / Transient response and frequency response plots...So component models should be fine....But just still wondering about the G & T units for phase...Thanks for the help