Note:
(1) Please use A4 size papers.
(2) Please use the SPICE model on page 2 for simulation and calculation.
1. [Current Source and Cascode Current Source]
(a) [20%] (Ξ» =ΜΈ 0 and Ξ³ = 0) Derive analytical expressions for the output impedance of current source (i) and (ii) below. (b)[40%](Ξ»=ΜΈ0andΞ³=0)ForVX =2V,Va =1.2V,Vb =2.2V, (W/L)1 = 20 ΞΌm / 2 ΞΌm, (W/L)2 = 100 ΞΌm / 2 ΞΌm, what are the output impedance values of current source (i) and (ii) below? Does the cascode structure significantly increase the output impedance?
(c) [10%] What are the minimum values of VX for M1 of circuit (i) and M2 of circuit (ii) to stay in the saturation region?
(d) [30%] For circuit (i) and (ii) below, plot the IX as a function of VX (from 0 V to 5 V) using Pspice in DC sweep mode. Confirm whether the hand-calculation results in (b) and (c) are consistent with the simulation results here.
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Vacuum permittivity (ππ¨) = π. ππ Γ ππβππ (F / m) Silicon oxide dielectric constant (ππ«) = π. π
