SIDDHARTH INSTITUTE OF ENGINEERING AND TECHNOLOGY

(Affiliated to J.N.T.U. Anantapuramu)

(Approved by A.I.C.T.E., New Delhi & Accredited by NBA, New Delhi)

(An ISO 9001- 2008 certified institutions)

DEPARTMENT OF ECE

Electronic Circuits Analysis & Design Lab

II B.TECH -II Semester (ECE)

PREPARED BY:

Mr. M.Marimuthu

Assistant Professor/ECE

(13A04405) ELECTRONIC CIRCUITS ANALYSIS AND DESIGN LAB

List of Experiments (12 experiments to be done):

Course Objective:

·  Help students make transition from analysis of electronic circuits to design of electronic circuits.

·  To understand the Analysis of transistor at high frequencies

·  To understand the concept of designing of tuned amplifier

·  The student will construct and analyze voltage regulator circuits.

·  To understand the circuit configuration and the principle operation of converters, including diode rectifiers, controlled AC-DC converters and DC choppers

Learning Outcome:

·  The ability to analyze and design single and multistage amplifiers at low, mid and high frequencies.

·  Designing and analyzing the transistor at high frequencies.

·  Determine the efficiencies of power amplifiers.

·  Determine Frequency response and design of tuned amplifiers.

·  Able to analyze all the circuits using simulation software and Hardware.

I) Design and Simulation in Simulation Laboratory using Any Simulation Software

(Minimum of 6 Experiments):

  1. Common Emitter Amplifier
  2. Common Source Amplifier
  3. A Two Stage RC Coupled Amplifier.
  4. Current shunt and Voltage Series Feedback Amplifier
  5. Cascade Amplifier
  6. Wien Bridge Oscillator using Transistors
  7. RC Phase Shift Oscillator using Transistors
  8. Class A Power Amplifier (Transformer less)
  9. Class B Complementary Symmetry Amplifier
  10. High Frequency Common base (BJT) / Common gate (JFET) Amplifier.

II) Testing in the Hardware Laboratory (6 Experiments)

Any Three circuits simulated in Simulation laboratory

Any Three of the following

  1. Class A Power Amplifier (with transformer load)
  2. Class C Power Amplifier
  3. Single Tuned Voltage Amplifier
  4. Hartley & Colpitt’s Oscillators.
  5. Darlington Pair.

6.  MOSFET Amplifier

INDEX

S.NO / DATE / NAME OF THE EXPERIMENT / MARKS OBTAINED / SIGNATURE OF FACULTY
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
AVERAGE MARKS

CYCLE – I

SOFTWARE EXPERIMENTS

  1. Common Emitter Amplifier
  2. A Two Stage RC Coupled Amplifier.
  3. Voltage Series Feedback Amplifier
  4. Wien Bridge Oscillator using Transistors
  5. RC Phase Shift Oscillator using Transistors
  6. Class A Power Amplifier (Transformer less)

1. Common Emitter Amplifier

Aim:

To simulate the Common Emitter amplifier using p-spice software and obtain the frequency response characteristics of CE amplifier

Apparatus Required:

S.No / Components
1 / Personal Computer
2 / Orcad Software

THEORY:

The practical circuit of CE amplifier is shown in the figure. It consists of different circuit components. The functions of these components are as follows:

1. Biasing Circuit: The resistances R1, R2 and RE form the voltage divider biasing circuit for the CE amplifier. It sets the proper operating point for the CE amplifier.

2. Input capacitor C1: This capacitor couples the signal to the transistor. It blocks any dc component present in the signal and passes only ac signal for amplification. Because of this, biasing conditions are maintained constant.

3. Emitter Bypass Capacitor CE: An emitter bypass capacitor CE is connected in parallel with the emitter resistance, RE to provide a low reactance path to the amplified ac signal. If it is not inserted, the amplified ac signal passing through RE will cause a voltage drop across it. This will reduce the output voltage, reducing the gain of the amplifier.

4. Output Coupling Capacitor C2: The coupling capacitor C2 couples the output of the amplifier to the load or to the next stage of the amplifier. It blocks DC and passes only AC part of the amplified signal.

Circuit Diagram:

Model Graph:

Procedure:

1. Open P-Spice Software to design Common Emitter amplifier circuit

2. Select on New editor window and place the required components.

3. Make the connections using wire and set oscillator (FG) frequency & amplitude.

4. Check the connections and the specification of components value properly.

5. Go for simulation using Run Key observe the output waveforms on CRO

6. Indicate the node names and go for AC Analysis with the output node

7. Observe the Ac Analysis and draw the magnitude response curve

8. Calculate the bandwidth of the amplifier

RESULT:

A common emitter amplifier using BJT was designed and its frequency response is obtained. From the frequency response curve the following results are calculated

2. Two stage RC coupled amplifier

Aim:

To simulate the Two stage RC coupled amplifier using p-spice software and obtain the frequency response characteristics of CE amplifier

Apparatus Required:

S.No / Components
1 / Personal Computer
2 / Orcad Software

THEORY:

An amplifier is the basic building block of most electronic systems. Just as one brick does not make a house, a single-stage amplifier is not sufficient to build a practical electronic system. The gain of the single stage is not sufficient for practical applications. The voltage level of a signal can be raised to the desired level if we use more than one stage.

When a number of amplifier stages are used in succession (one after the other) it is called a multistage amplifier or a cascade amplifier. Much higher gains can be obtained from the multi-stage amplifiers. In a multi-stage amplifier, the output of one stage makes the input of the next stage. We must use a suitable coupling network between two stages so that a minimum loss of voltage occurs when the signal passes through this network to the next stage.

Also, the dc voltage at the output of one stage should not be permitted to go to the input of the next. If it does, the biasing conditions of the next stage are disturbed

This is the most widely used method. In this scheme, the signal developed across the collector resistor RC (R2) of the first stage is coupled to the base of the second stage through the capacitor CC.(C2) The coupling capacitor blocks the dc voltage of the first stage from reaching the base of the second stage.

In this way, the dc biasing of the next stage is not interfered with. For this reason, the capacitor CC (C2) is also called a blocking capacitor. As the number of stages increases, the gain increases and the bandwidth decreases. RC coupling scheme finds applications in almost all audio small-signal amplifiers used in record players, tape recorders, public-address systems, radio receivers, television receivers etc.

Circuit Diagram:

Model Graph:

Procedure:

1. Open P-Spice Software to design Common Emitter amplifier circuit

2. Select on New editor window and place the required components.

3. Make the connections using wire and set oscillator (FG) frequency & amplitude.

4. Check the connections and the specification of components value properly.

5. Go for simulation using Run Key observe the output waveforms on CRO

6. Indicate the node names and go for AC Analysis with the output node

7. Observe the Ac Analysis and draw the magnitude response curve

8. Calculate the bandwidth of the amplifier

RESULT:

A Two stage RC coupled amplifier using BJT was designed and its frequency response is obtained. From the frequency response curve the following results are calculated

3. VOLTAGE SERIES FEEDBACK AMPLIFIER

Aim:

To simulate the frequency response characteristics of voltage series feed back amplifier.

Apparatus Required:

S.No / Components
1 / Personal Computer
2 / Orcad Software

THEORY:

When any increase in the output signal results into the input in such a way as to cause the decrease in the output signal, the amplifier is said to have negative feedback. The advantages of providing negative feedback are that the transfer gain of the amplifier with feedback can be stabilized against variations in the hybrid parameters of the transistor or the parameters of the other active devices used in the circuit.

The most advantage of the negative feedback is that by proper use of this, there is significant improvement in the frequency response and in the linearity of the operation of the amplifier. This disadvantage of the negative feedback is that the voltage gain is decreased. In Current-Series Feedback, the input impedance and the output impedance are increased. Noise and distortions are reduced considerably.

PROCEDURE:

1. Open P-Spice Software to design Common Emitter amplifier circuit

2. Select on New editor window and place the required components.

3. Make the connections using wire and set oscillator (FG) frequency & amplitude.

4. Check the connections and the specification of components value properly.

5. Go for simulation using Run Key observe the output waveforms on CRO

6. Indicate the node names and go for AC Analysis with the output node

7. Observe the Ac Analysis and draw the magnitude response curve

8. Calculate the bandwidth of the amplifier

Circuit Diagram:

MODEL GRAPH:

FREQURENCY RESPONSE:

RESULT:

Thus voltage series feed back amplifier was simulated and verified

4. WEIN BRIDGE OSCILLATOR

AIM

To simulate a wein bridge oscillator and to observe its output waveform

APPARATUS REQUIRED

S.No / Components
1 / Personal Computer
2 / Orcad Software

THEORY

Wein Bridge Oscillator uses a non inverting amplifier and hence does not produce any phase shift during amplifier stage as total phase shift req. is 0. In wein bridge oscillator type no phase shift is necessary through Feedback. Thus the total phase shift around a loop is 0.

DESIGN PROCEDURE:

  1. Select approximate transistor and note down its specification such as

Vce, Vcc(max), hoe(min), hfe(max) and Vbe(sat).

Vcc=VCEQ+ICQ(RC+RE)

  1. Assuming appropriate stability factor and hence I2 flowing through the biasing resistor and differentiator.
  2. Determine R1 and R2.
  3. Using the condition for sustained oscillation R3>2R4, compute C for designed frequency for the frequency of oscillator.

F=1/2πRC

PROCEDURE:

1. Open P-Spice Software to design Common Emitter amplifier circuit

2. Select on New editor window and place the required components.

3. Make the connections using wire and set oscillator (FG) frequency & amplitude.

4. Check the connections and the specification of components value properly.

5. Go for simulation using Run Key observe the output waveforms on CRO

6. Indicate the node names and go for AC Analysis with the output node

7. Observe the Ac Analysis and draw the magnitude response curve

8. Calculate the bandwidth of the amplifier

CIRCUIT DIAGRAM

MODEL GRAPH

RESULT:

Thus the Wein bridge oscillator was simulated and its output waveform was verified.

5. RC Phase Shift Oscillator

Aim:

To simulate RC phase shift oscillator in P-Spice and study the transient response

Apparatus Required:

S.No / Components
1 / Personal Computer
2 / Orcad Software

Theory:

The amplifier stage is self biased with a capacitor by passed source resistor (Rs) and

drain bias resistor (Rd). the expression for voltage gain of the amplifier is given by

Av =gm. rl.

The feedback network consists of three identical RC sections. Each section produces a phase

Shift of 60degree. Therefore the net phase shift of the feedback network is 180 degree. Since the amplifier stage also introduces a phase shift of 180°, therefore total phase shift is 360° or 0°.For the variable frequency oscillators, the three capacitors are ganged and varied simultaneously. When the circuit is energized by switching on the supply, the circuit starts oscillating. The oscillations may start due to the minor variation in dc supply or inherent noise.

PROCEDURE:

1. Open P-Spice Software to design Common Emitter amplifier circuit

2. Select on New editor window and place the required components.

3. Make the connections using wire and set oscillator (FG) frequency & amplitude.

4. Check the connections and the specification of components value properly.

5. Go for simulation using Run Key observe the output waveforms on CRO

6. Indicate the node names and go for AC Analysis with the output node

7. Observe the Ac Analysis and draw the magnitude response curve

8. Calculate the bandwidth of the amplifier

Circuit Diagram:

Model Graph:

RESULT:

A RC Phase Shift Oscillator was simulated and verified

6. Class-A Power Amplifier.

AIM:

To simulate a Class A power amplifier and observe the waveform

APPARATUS REQUIRED

S.No / Name
1 / Personal Computer
2 / Orcad Software

THEORY:

The power amplifier is said to be Class A amplifier if the Q point and the

input signal are selected such that the output signal is obtained for a full input signal cycle.

For all values of input signal, the transistor remains in the active region and never

enters into cut-off or saturation region. When an a.c signal is applied, the collector voltage

varies sinusoidally hence the collector current also varies sinusoidally.The collector current

flows for 3600 (full cycle) of the input signal. i e the angle of the collector current flow is

3600

PROCEDURE:

1. Open P-Spice Software to design Common Emitter amplifier circuit

2. Select on New editor window and place the required components.

3. Make the connections using wire and set oscillator (FG) frequency & amplitude.

4. Check the connections and the specification of components value properly.

5. Go for simulation using Run Key observe the output waveforms on CRO

6. Indicate the node names and go for AC Analysis with the output node

7. Observe the Ac Analysis and draw the magnitude response curve

8. Calculate the bandwidth of the amplifier

FORMULA:

Maximum power transfer =Po,max=Vo2/RL

Effeciency,η = Po,max/Pc

Circuit diagram

FREQUENCY RESPONSE