Question

Part I:

For the MOSFET differential amplifier discussed in the last class (having a tail resistor RSS and two drain resistors RD), draw its small signal ac equivalent and analyze it to determine the output voltage v_o (from M2 drain) in terms of the two ac inputs v₁ and v₂.

You should find a function of this form:

= (A₁)v₁ + (A₂)v₂

Part II:

a) Is A₁= - A₂? If no what does that mean?

b) Rewrite your output such that it reads as:

= A_d(v₁ -v₂)+A_cm(v₁ +v₂)/2

That is find A_d and A_cm as functions of A₁ and A₂.

Answer 1