Consider the amplifier circuit with two MOSFETs. Circuit is biased using a DC vo
ID: 1716917 • Letter: C
Question
Consider the amplifier circuit with two MOSFETs. Circuit is biased using a DC voltage supply (V_ DD) and DC current supply (Is). Both MOSFETs have the same threshold voltage V_TN=2V and same channel length L= L_1=L_2 K_N2= k(W_2/L)= ImA/V^2 K_N1= k(W_1/L) is adjusted by selecting W_1 What is the value of drain current for Q_2(I_D2)? What is the operating condition of Q2 ? Justify your answer. What is the operating condition of Q_1 ? Justify your answer. Construct small signal model, evaluate voltage gain, V_ out/v_ in(the capacitor can be approximated as a short circuit in this case) How does the gain depend on W_ 1? Evaluate input and output resistances and construct the 2-port model for the amplifier.Explanation / Answer
a) id2= kn (Vdd - Vt)2
= 64 mA
b) Vds = Vdd - Vt = 8
operaing condition = ( 64, 8),
c) operating onditio of Q1 -= (8,800)
D) VOUT/Vin = 100/10 = 10
e) input impedance = R1= 100
output impedance = 10//0.1= 0.99