Specialization: Micro Electronics

Question 1) Consider the Half-wave rectifier with RC load given below.

Find the value of the dc output voltage, ripple voltage, conduction interval and conduction angle for the circuit having a secondary voltage of 12.6 V_rms(60 Hz) with

R = 15 Ω

C = 25,000 μF

Assume the diode on-voltage V_on = 1 V.

Question 2) Design the stage of the circuit given below to satisfy the following conditions:

I_c = 1mA.

Voltage drop across R_L = 400 mV.

Voltage gain = 20 in the audio frequency range (20 Hz to 20 kHz).

Input impedance > 2 kΩ.

Assume

β = 100

I_s = 5 x 10^-16 A

V_cc = 2.5 V

Question 3) Design the non-inverting amplifier shown in the figure below for the following specifications.

Closed-loop gain =5.

Gain error = 1%

Closed-loop band width = 50 MHZ.

Determine the required open-loop gain and bandwidth of the operational amplifier. Assume the operational amplifier has an input bias current of 0.2 μA.

Question 4) Compute the error in I_copy1 and I_copy2 in the below figure, before and after adding a follower.

Where, A_E and 10A_E denote one unit and 10 unit transistors respectively.

Calculate I_copy1 if one of the four unit transistors is omitted, that is, the reference transistor has an area of 3A_E.

Question 5) Find the small-signal gain, input and output resistance of the amplifier in the figure below for the idealized case with R_i = ∞.

Use

βF = 150

VA = 50 V