The n-channel MOSFET shown in the figure operates with drain current ID = 0.4 mA and VD = 1.0 V. The transistor has VGS(th) = 2.0 V, unCox = 20uA/V2, L = 10um and W = 400um. Determine its drain resistance RD and source resistance RS.
Suppose a signal source Vgen has a Thevenin-equivalent circuit resistance Rgen = 50k as shown below, and is connected through terminals 1 and 2 to a load resistance RL = 600 : Calculate the voltage loss LdB = 20log10(Vgen/VL) for this circuit. Conventionally, loss in dB is a positive number, which is why the source voltage is on top in the fraction.
Assume the source follower is connected as a buffer amplifier between terminals 1 and 2 of the first figure (instead of the wire shown connecting them originally). The capacitors are large enough to act as short circuits at the frequency of interest. Find a value for RG that makes the AC voltage at the gate vg = 0.8Vgen. Then calculate the buffer amplifier gain VL/vg = AV, using the formula AV = RL/ 1/gm+RL Finally, calculate the buffered lossLB = 20log10(Vgen/VL) with the buffer inserted in the circuit. The value of LB should be considerably smaller than the original L, showing that although source followers have a voltage gain less than 1 , they can prevent significant losses when impedances are mismatched as at the beginning of this problem.
For the circuit shown below, calculate the ratio of (W/L)n /(W/L)p for the provided input and output voltages. All nMOS transistors have same sizes and the transistors' parameters (NMOS and PMOS) are as follow: un=550 cm2/Vs, up=275 cm2/Vs, Esio2=3.9, eo=8.85*10-14 F/cm, tox=0.16 nm, Vthn=0.5V, Vthp=-0.5V, VDD=3.6V, (Note: Cox= ( ESi02*e0)/ tox))
In Fig. 11, gm1 = 100uA/V, gm2 = 20uA/V, CL = 1pF. Ignore other parasitic capacitances. (a) Determine the transfer function Vout /Vin (s). (10) (b) Let's suppose that for a dc input of Vin = 1 V, Vout = 2 V. If Vin(t) = 1[V] + 1[mV]u(t), where u(t) is a unit step function at t = 0, determine Vout (t). (10)
For the circuit of Figure 9.1, the BJT (Q1) has B = 100 and VBE = 0.7V, and the (ideal) Zener diode has a breakdown current IZK = 10mA. The unregulated supply voltage VUR is a sawtooth signal that ripples between 19V and 21V. (a) If the circuit is designed to provide a 10V-1A regulated power supply to a load RL, determine the Zener voltage Vz required and the maximum value of R1 allowable. (b) If this maximum value of R1 is used, find the required minimum power ratings of the Zener diode and the series pass transistor Q1. [(a) 10.7V, 417ohm; (b) 264.3mW, 11W]