Repeat the calculations in Problem 7.14 for the common-source stage in Fig. 7.2b. Take V_DB= 7.5 V and I_D= 0.5 mA. Use the same transistor data and resistor values as in Problem 7.2 with the following exceptions:

1. C_ox and C_gd are not given, but f_T = 3 GHz.

2. C_db is not equal to 0. Calculate the zerobias drain-bulk capacitance as C_db0 = A_D (C_j0) + P_D (C_jsw0), where A_D = (5 µm)W, and use P_D = W. Let C_j0 = 0.4 fF/(µm²) and C_jsw0 = 0.4 fF/µm. Then use (1.202) with ψ₀ = 0.6 V to calculate C_db.

Data from Prob. 7.14:

Calculate the low-frequency small-signal voltage gain Ï…_o/Ï…_i and use the zerovalue time-constant method to estimate the ˆ’3-dB frequency for R_S = 10 kΩ and R_L = 5 kΩ. Data: β = 200, f_T = 600 MHz (at I_C = 1mA), C_μ = 0.2 pF, C_je = 2 pF, C_cs = 1 pF, r_b = 0, r_o = ˆž, and I_C = 1 mA.

Fig. 7.2 b:

RL Vo Rs Vi