8.2 For VDD = 1.2 V and using IREF = 10 μA, it is required to design the circuit of Fig. 8.1 to obtain an output current whose nominal value is 60 μA. Find R and W2 if Q1 and Q2 have equal channel lengths of 0.4 μm, W1 = 1 μm, Vt = 0.4 V, and kn′ = 400 μA/V2. What is the lowest possible value of VO ? Assuming that for this process technology, the Early voltage VA′ = 6 V/μm, find the output resistance of the current source. Also, find the change in output current resulting from a +0.2−V change in VO. Figure 8.1 Circuit for a basic MOSFET constantcurrent source. For proper operation, the output terminal, that is, the drain of Q2, must be connected to a circuit that ensures that Q2 operates in saturation.
An enhancement-type nMOS transistor has the following parameters: a) Determine the size of the transistor (W/L) if the transistor is biased with VG=5 V, VD=4 V, Vs =0.5 V, VB=0 V, and the drain current is lD=150uA b) If VG=5V, VD=4V, Vs=1 V, and VB=0 V, find the value of drain current (lD). c) Determine the value of W and L, if un = 650 cm2/V.s and Cg = Cox.W.L = 10
Label the voltage swing (max and min voltage) at each node connected to a box, given that the inputs to the system vary between two states: A = 2.5 V and B = 0 V and A = 0 V and B = 2.5 V Assume the threshold voltage is 0.5 volt, and Vdd is 2.5 V unless marked.
(a) When the transistor is biased with VG = 2.8 V, VD = 5 V, Vs = 1 V, and VB = 0 V, the drain current is ID = 0.24 mA. Determine W/L. (b) Calculate ID for VG = 5 V, VD = 4 V, VS = 2 V, and VB = 0 V. (c) If un = 500 cm2/Vs and Cg = CoxWL = 1.0 x 10-15 F, find W and L. An enhancement-type nMOS transistor has the following parameters: VT0 = 0.8V y = 0.2 V1/2 lambda = 0.05 V-1 |2phif| = 0.58 V k