TAMPERE UNIVERSITY OF TECHNOLOGY
Institute of Communications Engineering
Problem Max. Points Result
1
2
3
10
10
10
4
5
10
10
Total: 50
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Given Name:
Student Number:
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Final Mark:
Please, write your answers in English.
2006/2007
Examination 2
15.01.2007
!

TLT-8016 Basic Analog Circuits 2006/2007 Examination 2 15.01.2007
Problem 1 10 pt.
Define briefly the following terms and answer shortly to the questions (1pt per correct answer):
1.
Current gain;
2.
Power gain;
3.
Inverting and non-inverting amplifier;
4.
Ideal voltage amplifier;
5.
Ideal current amplifier;
6.
Rise time;
7.
Current gain β of BJT;
8.
Draw the circuit symbol of an npn BJT and show the BJT terminals in it;
9.
Poles and zeros;
10.
Low-pass, high-pass and band-pass filter.
2

TLT-8016 Basic Analog Circuits 2006/2007 Examination 2 15.01.2007
Problem 2 10 pt.
Consider the cascade connection of two amplifiers shown in Figure 2.1. Find the current gain, voltage gain, and power gain of each stage and for the overall cascade connection.
R o1
R o2
+ v i1
R i1
1M Ω
-
200v i1
500 Ω + v i2
-
R i2
1500 Ω
100 Ω
100v i2
+ v o2
-
R
L
100 Ω
Amplifier 2 Amplifier 1
Figure 2.1.
3

TLT-8016 Basic Analog Circuits 2006/2007 Examination 2 15.01.2007
Problem 3 10 pt.
Plot the circuit of the inverting amplifier, realized with operational amplifier. Derive the formula for its voltage gain, input and output impedance.
4

TLT-8016 Basic Analog Circuits 2006/2007 Examination 2 15.01.2007
Problem 4 10 pt.
In the Figure 4.1 below is given the family of the output characteristics of BJT 2N2222. Plot the load line, if the collector resistor R
C
is equal to 1 k Ω and the supply voltage V
CC
is equal to 9V, as it is shown in Figure 4.2. Determine the quiescent point, corresponding to base current not have plotting instruments plot the load line with free hand.)
I
B
equal to 20 µ A. (If you do
I
B
20 µ A
Figure 4.1.
R
C
1k Ω
V
CC
9V
-
+
Figure 4.2.
5

TLT-8016 Basic Analog Circuits 2006/2007
Problem 5
1. How the negative feedback affects:
(a) the gain;
(b) gain stability;
(c) nonlinear distortion;
(d) noise;
(e) input and output impedance?
2. Why the positive feedback is avoided in amplifiers?
Examination 2 15.01.2007
10 pt.
6