Consider the CMOS circuit shown, where the gate voltage of the n-MOSFET is increased from zero, while the gate voltage of the p-MOSFET is kept constant at 3 V. Assume that, for both transistors, the magnitude of the threshold voltage is 1 V and the product of the transconductance parameter and the $$\left(\frac WL\right)$$ ratio, i.e. the quantity $$\mu C_{ox}\left(\frac WL\right)$$ , is 1 mAV^-2.
Estimate the output voltage V₀ for V_G =1.5 V. [Hints: Use the appropriate current-voltage equation for each MOSFET, based on the answer]

Two identical NMOS transistors M₁ and M₂ are connected as shown below. V_bias is chosen so that both transistors are in saturation. The equivalent g_m of the pair is defined to be $$\frac{\partial I_{out}}{\partial v_i}$$ at constant V_out. The equivalent g_m of the pair is

For the circuit shown in the following figure, transistors M1 and M2 are identical NMOS transistors. Assume that M2 is in saturation and the output is unloaded The current I_x is related to I_bias as

The measured transconductance g_m of an NMOS transistor operating in the linear region is plotted against the gate voltage V_G at constant drain voltage V_D. Which of the following figures represents the expected dependence of g_m on V_G?