Calculate DC biasing (20 points), of the following circuits. |Vth| = 0.5 V, λ = 0, μCoxWL = 0.2 A/V2 for all devices. DC biasing means the biasing currents and the output voltages. If we keep the currents as calculated and try to minimize the vdd, what would be the the lowest vdd for the circuits. Assume PMOS's parameters are exactly the same as the NMOS (20 points).
For the circuit below, suppose C = 10 μf, R1 = 1000 Ω, R2 = 3000 Ω, R3 = 4000 Ω, Is = 1 mA. The switch closes at t = 0 sec. If Vc started with 0 V across it, what is the value of Vc (in volts) just prior to the switch closing? Assume that the switch had been open for a long time. Enter your answer in the box below without units. Enter answer here 2. For the circuit above, what is the value of Vc after the switch has been closed for a long time? Enter answer here 3. What is the time constant of the circuit (in seconds)? Enter the answer below without units. Enter answer here 4. What is the value of Vc at t = 2 msec (in volts). Enter the answer in the box below without units. Enter answer here
Question: For the AC equivalent circuit of a common-emitter BJT amplifier shown in Figure 1, assume that VCC = 10 V, VBE = 0.7 V, RS = 5 kΩ, RB = 100 kΩ, RL = 1 kΩ, Cb'e = 2 pF, Ccb′ = 1 pF, and CL = 1 pF. Assume bias current IB = 25 μA, Boltzmann's constant k = 1.38×10−23 J/K, q = 1.6 ×10−19 C, T = 300 K, VT = 26 mV, β = 100, rbb' = 100 Ω, and ignore ro. Assuming the equivalent noise bandwidth is 100 kHz, and neglecting the flicker noise and capacitive effect. Note: For the BJT biased on the forward active region: rπ = VT/IB, gm = IC/VT. (a) Calculate the total equivalent input rms noise voltage and current by looking into node a. (b) Calculate the total equivalent input rms noise voltage and current by looking into node b. (c) Discuss if a transformer (with turn ratio I:N) can be incorporated into point b to minimize the total input referred noise? If yes, what is the N to be? Figure 1