(a) Show that if all FETs in the circuit of Fig. 4.64b have the same and k, then, so long as the condition gmro @ 1 holds, the circuit gives CMRR > 2y(V OV) 2 , where VOV is the overdrive voltage...

(a) Show that if all FETs in the circuit of Fig. 4.64b have the same and k, then, so long as the condition gmro @ 1 holds, the circuit gives CMRR > 2y(V OV) 2 , where VOV is the overdrive voltage required to sustain the current ISSy2, and 5 0 has been assumed for simplicity. (b) Show that if the mirror supplying ISS is changed to a cascode type as in Fig. P4.95, then CMRR > √ __ 8 y( V OV) 3 . (c) Compare the two circuits if k 5 2 mA/V2 , 5 1y(15 V), and ISS 5 0.18 mA. (d) What happens if ISS is doubled? Halved?