Calculate the average power dissipation

2. You are to submit online of your answers in OAS system and it is your responsibility to submit your TMA correctly and timely. Marks will be awarded for correct working steps and answer.

3. The total marks for TMA 1 are 100 and contributes 25% towards the total grade.

(a) Sketch the I–V characteristics of a silicon diode. Label the sketched diagrams clearly. [5 marks]

(iii) Sketch v_s(t) and i(t) to scale against time. [5 marks]

Question 2 (25 marks)

(ii) Calculate the value of source resistance R_S required to bias the n-JFET in saturation region with gate-to-source voltage, V_GS = ‒3V. [10 marks]

(b) A MOSFET circuit is shown below. The parameters of the MOSFET are: V_tn = 2V and K = 0.6mA/V².

3. Calculate V_DS. [4 marks]

Question 3 (25 marks)

(a) Expression of I_E2 in terms of I_E1 [4 marks]

(b) Values of I_E1 and I_E2 [10 marks]

(a) In a class C amplifier, the transistor is turned on for 45⁰ of the input cycle in which the signal frequency is 500kHz. If the V_CE(sat) of the transistor is 0.20V, V_CC and load R_L of the amplifier are 20V and 50Ω respectively, calculate the average power dissipation. [5 marks]

(b) A Class B push-pull power amplifier is shown in the figure below.

3. Maximum DC input power. [4 marks]

4. Maximum AC output power. [4 marks]