The feedback circuit in Fig. 9.55 is a switched-capacitor circuit during one clock phase.

Assume the op amp is the telescopic-cascode op amp in Fig. 9.54. Take C_L= 1.5 pF, C_I = 4 pF, C_S = 0.4 pF, and C_ip = 0.1 pF.

(a) If I_TAIL= 0.2 mA, what is the output slew rate?

(b) Assume that g_m1= 0.1 mA/V, the loop trans-mission [loop gainT(s) or return ratio R(s)] can be modeled as having two poles, and the magnitude of the nondominant pole p₂ is |p₂| = 200 Mrad/s.

What is the phase margin of this feedback circuit?

Figure 9.55:

Transcribed Image Text:

C, Cs Cip V. CL