The cascode current source shown below must be designed for a bias current of 0.5 mA. Assume Kn = 5 mA/V2 and Vth = 0.4 V for both M1 and M2. (a) Neglecting channel-length modulation, compute the required value of Vb2. What is the minimum tolerable value of Vb1 if M2 must remain in saturation? (b) Assuming lambda = 0.1 V-1, calculate the output impedance of the circuit.
The cascode current source shown in Fig. 9.48 must be designed for a bias current of 0.5 mA. Assume unCox = 100 uA/V2 and VTH = 0.4 V. (a) Neglecting channel-length modulation, compute the required value of Vb2. What is the minimum tolerable value of Vb1 if M2 must remain in saturation? (b) Assuming lambda = 0.1 V-1, calculate the output impedance of the circuit.
The cascade current source shown below must be designed for a bias current of 1 mA. Assume unCox = 100 uA/V2 and VTH = 0.4V. (a) Neglecting channel-length modulation, compute the required value of Vb2. What is the minimum tolerable value of Vb1 if M2 must remain in saturation? (b) Assuming lambda = 0.1 V-1, calculate the output impedance of the circuit. Show all your work along with the small-signal equivalent circuit.