Fnd r and w for all transistors in order to get iref

Question

Problem 1. The amplifier below has a gain of 15 at I_D = 0.25 mA. Find (W/L)₁, and (W/L)₂ if λ_n - 0.05 /V, λ_P = 0.15/V, μ_pC_oz = 40 μA/V², and = 100 MA/V2 (Ignore channel-width modulation in biasing).

Let V_OV1 = V_OV2.

Problem 2. Consider the current steering circuit below with V_DD = 2.5 V, V_ov2 = V_ov3 Vey and the following device parameters: μ_nC_ox = 200 μA/V², μ_nC_ox = 80 μA/V², V_in = 0.4 V, V_tp = 0.4V, and λ = 0. All transistors have L = 0.5 μm and W_ref = 10 μm.

A) Find R and W for all transistors in order to get I_ref = 20μA, I₁= 100 μA, I₂ = I₃ = 20µA, and I₄ = 50 μ.

B)What is the minimum allowable value of V_D1.

C)What is the maximum allowable value of V_D4.

Problem 3.

Compute V_D, V_S, V_DS and V_GS if I_D3 = 2 mA, R_D = 500 Ω, V_ov3= 0.5 V. and identical Q1 & Q2 with μ_nC_ox (W/L) = 8 mA/V², V_t = 0.5 λ = O.

A) For V_G = 0, and B) For V_G = O. C) Repeat A and B for λ = 0.1V^-1 .