Response to the following problem:
Figure shows Amos differential amplifer with the drain resistors RD implemented using diode-connected PMOS transistors,Q3: and Q4:
Let Q1: and Q2: be matched, and Q3: and Q4: be matched
(a) Find the differential half-circuit and use it to derive an expression for Ad in terms of gm1,2, gm3,4, ro1,2, and ro3,4
(b) Neglecting the effect of the output resistances ro, find Ad in terms of μn, μp, (W/L)1,2 and (W/L)3,4.
(c) If μn =4μp and all four transistors have the same channel length, find (W1,2/W3,4) that results in Ad = 10 V/V.