In the common-source stage depicted in Fig. 7.66, the drain current of M1 is defined by the ideal current source I1 and remains independent of R1 and R2 (why?). Suppose I1 = 1 mA, RD = 500 Ω, λ = 0, and C1 is very large.
(a) Compute the value of W=L to obtain a voltage gain of 5.
(b) Choose the values of R1 and R2 to place the transistor 200 mV away from the triode region while R1 + R2 draws no more than 0.1 mA from the supply.
(c) With the values found in
(b), what happens if W/L is twice that found in (a)? Consider both the bias conditions (e.g., whether M1 comes closer to the triode region) and the voltage gain.
