Design the MOS peaking current source in Fig. 4.34 so that I_OUT= 0.1 µA.

(a) First, let I_IN = 1 µA and find the required value of R.

(b) Second, let R = 10 kΩ and find the required I_IN.

In both cases, assume that both transistors are identical and operate in weak inversion with I_t = 0.1 µA and n = 1.5. Also, find the minimum W/L in both cases, assuming that V_GS ˆ’ V_t < 0 is required to operate a transistor in weak inversion as shown in Fig. 1.45.

Fig. 4.34:

Fig. 1.45:

Transcribed Image Text:

VDD IN |IOUT M2 M1 30 (moderate inversion) From (1.254) with n = 1.5 (weak inversion) 20 From (1.181) (strong inversion) &m S (V-1) 15 10 O 2nVT VGs - V; (V) -0.5 -0.25 0.25 0.5 25