(a) For the op amp in Problem 12.5, calculate a€™_cm. Assume that the CMFB scheme in Fig. 12.17 is used and that a_cms= 1. Recall that a€™_cm= v_oc/v_icwhen the CMFB loop is active.

(b) Use SPICE to plot |a€™_cm| from 100 Hz to 100 MHz.

Fig. 12.17:

Data from Prob. 12.5:

Use the data from Problem 12.4 except use I_D5 = 100 µA and |V_ov| = 0.1 V for all transistors. Assume all transistors operate in the active region with C_gs = 180 fF And C_gd = 20 fF.

Vo1 =Voc = VGs Rs VCM - VGs