9.1 For an NMOS differential pair with a common-mode voltageVCM applied,asshowninFig. 9.2,letVDD = VSS = 1.0 V, k n = 0.4 mA/V2 , (W/L)1,2 = 10, Vt n = 0.4 V, I = 0.16 mA, RD = 5 k, and neglect channel-length modulation. (a) Find VOV and VGS for each transistor. (b) For VCM = 0, find VS , ID1, ID2, VD1, and VD2. (c) Repeat (b) for VCM = +0.4 V. (d) Repeat (b) for VCM = −0.1 V. (e) What is the highest value of VCM for which Q1 and Q2 remain in saturation? (f) If current source I requires a minimum voltage of 0.2 V to operate properly, what is the lowest value allowed for VS and hence for VCM ?