Design a MOS Widlar current source using the circuit shown in Fig. 4.31b to meet the following constraints with V_DD= 3 V:

(a) The input current should be 100 µA, and the output current should be 10 µA.

(b) V_ov1 = 0.2 V.

(c) Transistor M₂ must operate in the active region if the voltage from the drain of M₂ to ground is at least 0.2 V.

(d) The output resistance should be 50 MΩ.

Ignore the body effect. Assume L_drwn = 1 µm and X_d = L_d = 0. Use Table 2.4 for other parameters.

Fig. 4.31 (b):

Transcribed Image Text:

VDD IN IOUT ER, M2 M1 R2 (b)