(b) For a MOSFET current source shown in Figure 5 the circuit parameters are: V+ = 3 V and V − = −3 V. Transistor parameters for NMOS are: VTN = 0.7 V, kn′ = 200 μA/V2 and λn = 0.01 V−1; and the transistor parameters for PMOS are: VTP = −0.6 V, kp′ = 80 μA/V2 and λp = 0.03 V−1. The transistor aspect ratios are: (W/L)1 = 10, (W/L)2 = 35, (W/L)3 = 5 and (W/L)4 = 15. Find IO, IREF and the VGS voltages for all transistors if the minimum voltage at the drain of transistor M2, i.e. VD2 is −2.3 V. [12 Marks] Figure 5