Figure P8.75 shows a folded-cascode CMOS amplifier utilizing a simple current source Q2:
supplying a current 2I, and a cascoded current source (Q4:
Q5:
supplying a current I. Assume, for simplicity, that all transistors have equal parameters gm and ro.
(a) Give approximate expressions for all the resistances indicated.
(b) Find the amplifier output resistance Ro.
(c) Show that the short-circuit trans conductance Gm is approximately equal to gm1. Note that the short-circuit Trans conductance is determined by short-circuiting vo to ground and finding the current that flows through the short circuit, Gmvi .
d) Find the overall voltage gain vo/vi and evaluate its value for the case gm1 = 2 mA/V and A0 = 30.