AC Load Line Points

Thread Starter


Joined Nov 19, 2019
I am finishing my study of Class AB Power Amps. I have calculated the ac load line points
for the three stages. I would appreciate it if someone could verify my calculations (attached).
The stage 2 graph is a little weird.



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Joined May 20, 2015
I've seen your topics. But I looked at them and I wasn't interested. You have models in your schemes that I don't have. Like a potentiometer and a low-power npn transistor. I can also say that you're not defining the output resistance correctly. I mean...
.meas Zout find v(Vout)/i(RL) at 1Khz
is wrong!
I'll tell you how to do it. Equate the AC 0 input signal to zero. Increase the load resistance to 8TOhm. Connect a current parallel to the load DC 0A and AC 1A. Perform AC analysis. The voltage at the load will be numerically equal to the output resistance. You will see that at low frequencies, the output resistance is greater. Because of the separating capacitor.
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