Question

Design the MOSFET current mirror shown in Figure 2 to replicate a 1 mA reference current at the drain ofM2. Assume Vtn-1.2 V, L-100 μm, W-100 μm, kh-0.093 A/V2, and V,-100 1. Determine Ri such that IREF 1 mA is the current, Ipi, flowing into the drain of Mi. 2. Calculate lolREF, where lo = 1D2. 3. Simulate the circuit in Figure 2 in PSpice. Use the SEDRA LIB library for the MOSFET transistors and enter the appropriate parameters into the PSpice model 4. Compare the simulated DC currents to the calculations performed in Pre-lab Steps 1 and Explain any discrepancies.

Ignore PSpice Simulation

Answer 1

Given V_th = 1.2 V L = 100 mu m w = 100 mu m k n 6^1 0.093 A/V^2 V_A = 100 I_0 1 = 1/2 k n^1 (w/l)_1 (V_g_s V_t n)^2 I_ref = I_D i = 1 m A 1 mA = 1/2 times 0.093 times (100 times 10^-6/100 times 10^-6) (V_gs - 1.2)^2 (V_gs - 1.2)^2 = 0.0215 V_g s - 1.2 = squareroot 0.0215 V - as - 1.2 = 0.1466 V_gs = 1.3466 I_D i = I ref = V_DD - V_gs/R_1 R - 1 = V_D D - V_g s/I_ref = 10 - 1.3466/1 m A = 8.653 k ohm