Figure 1 shows the voltage transfer characteristic (VTC) of a CMOS inverter. Note that the VTC is a straight line for VIL < Vin < VIH. Subthreshold current for both nMOS and pMOS is strictly zero, meaning nMOS and pMOS are strictly off when Vgsn < Vthn and Vsgp > |Vthp| Use VDD = VOH = 1.8 V VOL = GND = 0 V, and VIH = 1.35 V b) (6 pts) Determine the threshold voltages Vthn and Vthp. d) (7 pts) Suppose VDD is reduced to 0.6 V without changing other parameters (same Vthp and Vthn). Sketch how the voltage transfer characteristic curve changes, and qualitatively describe the behaviour of the inverter operation if it is different from a typical inverter.