1 For an NMOS differential pair with a common-mode voltage VCM applied,as shown in Fig. 9.2,letVDD
=VSS =1.0 V, k1n = 0.4 mA/V2, (W/L)1,2 = 10, Vtn = 0.4 V, I = 0.16 mA, RD = 5 kΩ 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 CM =+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?