Q. Consider the MOSFET circuit with variable voltage, with RD = 2k and VDD = 12 V. The static characteristics of
the n-channel enhancement MOSFET are given in Figure.

(a) Drawthe load line and find the operating point if vGS = 4V.

(b) Sketch the resulting transfer curves (i.e., iD and vDS as a function of vGS) showing cutoff, active, and saturation regions.

(c) For relatively undistorted amplification, the MOSFET circuit must be restricted to signal variations within the active region. Let vGS (t) = 4 + 0.2 sin ωt V. Sketch iD(t) and vDS(t), and estimate the resulting voltage amplification Av.

(d) Let vGS (t) = 6 sin ωt , where ω is slow enough to satisfy the static condition. Sketch iD(t) and vDS(t) obtained from the transfer curves. Comment on the action of the MOSFET in the switching circuit.