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Electronic Filters andAmplifiers EEET 4062,

SP5, 2013

Assignment

(50%)

1) Draw and determine the voltage gain (Av = vo/vi ), input impedance and output

impedance of the following amplifier configurations (hint, draw a circuit for each

and its ac equivalent using the hybrid model):

a. Common base

b. Common emitter

c. Common collector

d. Discuss the difference between the three amplifier configurations and their

applications.

(Hint: page 269 is a good place to start)

2) For the Single Time Constant Networks in Figure 1, determine:

a. The time constant ()

b. The transfer function (Av = vo/vi) [hint: Zc = 1/(CS)]

c. Given that C = 100nF and R = 1.0 k, sketch and dimension the Bode plot(magnitude and phase) over an appropriate frequency range.

Figure 1a Figure 1b

Figure 1c Figure 1d

(Hint: to begin, study page 1073, 1074)

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3) For the transistor Circuit in Figure 2.

a. Explain the effect of coupling and bypass capacitors on the low frequency response of

the typical amplifier.b. Using the hybrid model draw a low frequency ac equivalent circuit for the circuit in

Figure 2.

c. Explain the effect of internal capacitors on the high frequency response of the typical

amplifier.

d. Draw a high frequency ac equivalent circuit for the circuit in Figure 2.

Figure 2

(Note that the high frequency model of the transistor is on page 606).

4) Explain including diagrams, the four basic types of feedback as seen in

(a) Voltage Amplifiers page 769

(b) Current Amplifiers page 771(c) Transresistance Amplifiers page 775

(d) Transconductance Amplifiers page 774

5) Explain the Miller Theorem result and give a derivation (see page 644).

How is this applicable to the high frequency hybrid equivalent circuit for theBJT as shown on page 712.

VCC

= 10

volts

R1

7900

R2

3900

RC

1500

RE

1200

RL

1000

CC1

10 F

CC2

10 F

CB

100 F

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6) Draw and explain the operation of the following oscillators, and the formulae

for their operating frequencies and feedback fractions:

a. The typical circuit of a Phase Shift Oscillator. (page 1145)

b. The typical circuit of a Colpitts Oscillator. (page 1154)

c. The typical circuit of a Crystal Oscillator. (page 1157)

7) Explain the following aspects of electronic filters:

a. Explain the five basic responses of filters. (page 1061)

b. Describe two filter approximation methods used in designing filters

c. Draw a first order RC low pass passive filter. Find the value of a resistor to

get a 3-dB frequency of 100 Rad/Sec. [Given: C = 100 nF.]

(page 1072, 1074)

8) Draw the circuit of a typical second order Sallen-Key low-pass filter having a pass

band gain of unity and explain its operation. (page 1105)

9) Explain, with diagrams, the operation of a tuned amplifier. (page 1114)

What is the difference between a series and a parallel LC circuit? (page 1115)

Explain the significance of C in figure 11.40 on page 1117.

10) Explain how and why the efficiency of a power amplifier is made high.(page1195)

Explain what crossover distortion is, and how it is eliminated. (page 1206)

Comment on class C, class D and class S amplifiers and their efficiencies.

(page 1224)

11) Bonus question

Analyse the following common base circuit.

Calculate the DC values VB, VE, IE and r.

Show the small signal equivalent circuit.

Give expressions for vout and vin.

Hence calculate Av, Zin and Zout.

Figure 3 Dr P. Cooke 8/13

VCC

= 10

volts

R110 k

R2

2200 R

E

2200

RL

10 k

CC1

47 F

CC2

1 F

RC

3600

CB

47 F

vS

vout

DC

=400

AC=250

.

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Sedra, A. and Smith K. 2009, Micro-electronic Circuits, 6, Oxford Press.

This is the book name