aryajur
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Differential Amp gain
I have a simple Bipolar Differential Amplifier with a BJT input stage. The equivalent circuit I have drawn and attached. When I do an AC simulation of the diff amp, giving a 500m and -500m signals at the inputs, I get the output which looks like the one I have attached.
The differential gain of the output looks around 0.4 which was about right for my circuit. But it shows a common mode gain of 5, why I am I getting such a huge common mode gain? The tail current is implemented using a MOS current source.
I have a simple Bipolar Differential Amplifier with a BJT input stage. The equivalent circuit I have drawn and attached. When I do an AC simulation of the diff amp, giving a 500m and -500m signals at the inputs, I get the output which looks like the one I have attached.
The differential gain of the output looks around 0.4 which was about right for my circuit. But it shows a common mode gain of 5, why I am I getting such a huge common mode gain? The tail current is implemented using a MOS current source.