SCHOOL OF ELECTRICAL ENGINEERING
EEE2002- Semiconductor Devices and Circuits
ASSIGNMENT -2
1.
A half-wave rectifier has a 2 kΩ load. The input is a 120 V (rms), 60 Hz signal and the transformer is a
10:1 step down transformer. The diode has a cut-in voltage of Vγ = 0.7 V (rf = 0). (a) What is the peak
output voltage? (b) Determine the peak diode current (c) What is the fraction (percent) of a cycle that v0 > 0
(d) Determine the average output voltage? (e) Find the average current in the load.
2.
Discuss about the shunt voltage regulator realized using zener diode.
3. Design the biasing network for the following circuits i) base bias, ii) base bias with emitter feedback and
iii) base bias with collector feedback for the given Q point values of IcQ= 5 mA and VCEQ= 12V.
Assume supply voltage of 15V and β of 100. Prepare a table and compare the bias voltage and current
values for a new value of β = 200. Compare the changes in IC and VCE for the same increase in β.
4.
For the network of Fig.1 , determine: (a) IE (b) VC (c) VCE.
Fig. 1
5.
For the voltage feedback network of Fig. 2, determine: (a) IC (b) VC (c) VE (d) VCE.
Fig. 2
6.
Determine the voltage gain, input and output impedance for the following BJT amplifier shown in Fig. 3.
Fig. 3.
7.
i) Using the characteristics of Fig. 4, determine the resulting collector current if IE 4.5 mA and VCB 4V.
ii) Repeat part (i) for IE 4.5 mA and VCB 16 V.
iii) How have the changes in VCB affected the resulting level of IC?
iv) On an approximate basis, how are IE and IC related based on the results above?
Fig. 4