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Dr.NNCE ECE/IVSEM LIC LAB-LM

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EC2258 - LINEAR INTEGRATED CIRCUITS LABORATORY

LABORATORY MANUAL

FOR IV SEMESTER B.E (ECE)

ACADEMIC YEAR(2013-2014)

(FOR PRIVATE CIRCULATION ONLY)

ANNA UNIVERSITY CHENNAI-600 025

(REGULATION 2008)

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

ENGINEERING

DR.NAVALAR NEDUNCHEZHIYAN COLLEGE OF ENGINEERING

THOLUDUR – 606303, CUDDALORE DISTRICT


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HARDWARE REQUIREMENTS:

CRO (30/60 MHz)

FUNCTION GENERATOR (1 MHz Range)

REGULATED POWER SUPPLY (0-30)

DUAL POWER SUPPLY (±15V/± 12V)

BREAD BOARD

TRANSFORMER & CONSUMABLES

ALLOTMENT OF MARKS

INTERNAL ASSESMENT : 20 MARKS

PRACTICAL EXAM : 80 MARKS

TOTAL : 100 MARKS

INTERNAL ASSESMENT (20 MARKS)

SPLIT UP OF INTERNAL MARKS

OBSERVATION : 3 MARKS

RECORD NOTE : 7 MARKS

CIA I : 2 MARKS

CIA II : 2 MARKS

MODEL EXAM : 3 MARKS

ATTENDANCE : 3 MARKS

TOTAL : 20 MARKS

UNIVERSITY EXAMINATION

The Exam will be conducted for 100 marks. Then the marks will be converted to 80 marks.

ALLOCATION OF MARKS

Aim and Result : 10 marks

Circuit diagram and Tabulation : 20 Marks

Connection : 30 Marks

Output : 30 Marks

Viva Voce : 10 Marks

Total : 100 Marks


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GENERAL INSTRUCTIONS FOR LABORATORY CLASSES

Enter the Lab with CLOSED FOOTWEAR.

Boys should “TUCK IN” the shirts.

Students should wear uniform only.

LONG HAIR should be protected, let it not be loose especially near ROTATING

MACHINERY.

Any other machines / equipments should not be operated other than the prescribed one

for that day.

POWER SUPPLY to your test table should be obtained only through the LAB

TECHNICIAN.

Do not LEAN and do not be CLOSE to the rotating components.

TOOLS, APPARATUS and GUAGE sets are to be returned before leaving the lab.

HEADINGS and DETAILS should be neatly written

Aim of the experiment

Apparatus / Tools / Instruments required

Procedure / Theory / Algorithm / Program

Model Calculations

Neat Diagram / Flow charts

Specifications / Designs Details

Tabulations

Graph

Result / discussions.

Before doing the experiment, the student should get the Circuit / Program approval by

the FACULTY -IN -CHARGE.

Experiment date should be written in the appropriate place.

After completing the experiment, the answer to the viva-voce questions should be neatly

written in the workbook.

Be PATIENT, STEADY, SYSTEMATIC AND REGULAR.


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LIST OF EXPERIMENTS

1. Inverting, Non-inverting and Differential amplifiers.

2. Integrator and Differentiator.

3. Instrumentation amplifier.

4. Active lowpass, Highpass and Bandpass filters.

5. Astable and Monostable multivibrators and Schmitt trigger using Op-Amp.

6. Phase shift and Wien bridge oscillators using Op-Amp.

7. Astable and Monostable multivibrators using NE555 timer.

8. PLL characteristics and its use as frequency multiplier.

9. DC power supply using LM317 and LM723.

10. Study of SMPS.

11. Simulation of Instrumentation amplifier using PSpice.

12. Simulation of Active lowpass, Highpass and Bandpass filters using PSpice.

13. Simulation of Astable and Monostable multivibrators and Schmitt trigger using

PSpice.

14. Simulation of Phase shift and Wien bridge oscillators using PSpice.

15. Simulation of Astable and Monostable multivibrators using PSpice.


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Ex. No Name of the Experiment Page No.

01 Inverting, Non-inverting and Differential amplifiers

02 Integrator and Differentiator

03 Instrumentation amplifier

04 Active lowpass, Highpass and Bandpass filters

05 Astable and Monostable multivibrators and Schmitt trigger

using Op-Amp

06 Phase shift and Wien bridge oscillators using Op-Amp

07 Astable and Monostable multivibrators using NE555 timer

08 PLL characteristics and its use as frequency multiplier

09 DC power supply using LM317 and LM723

10 Simulation of Instrumentation amplifier using PSpice

11 Simulation of Active lowpass, Highpass and Bandpass filters

using PSpice

12 Simulation of Astable and Monostable multivibrators and

Schmitt trigger using PSpice

13 Simulation of Phase shift and Wien bridge oscillators using

PSpice

14 Simulation of Astable and Monostable multivibrators using

PSpice

15 Study of SMPS

CONTENTS


6

PIN DIAGRAM:

CIRCUIT DIAGRAM:

INVERTING AMPLIFIER:

MODEL GRAPH:


7

Exercise/Experiment Number: 1

Title of the exercise/experiment : Inverting, Non-inverting and Differential amplifiers

Date of the experiment :

INTRODUCTION

OBJECTIVE (AIM) OF THE EXERCISE/EXPERIMENT

To construct and test the performance of an Inverting, Non-inverting amplifier and

Differential amplifier using IC µA 741

ACQUISITION

A. APPARATUS REQUIRED:

B. DESIGN:


Let A = -5; R1 = 1KΩ

A = − Rf / R1

Rf = 5 KΩ

Rcomp = R1 Rf / R1 + Rf

= 833 Ω

NON-INVERTING AMPLIFIER:

Let A = 6; R1 = 1KΩ

A = 1 + (Rf / R1)

Rf = 5 KΩ

Rcomp = R1 Rf / R1 + Rf

= 833 Ω

NON-INVERTING AMPLIFIER:

Let A = 100; R1 = 1KΩ

A = R2 / R1

R2 = 100 KΩ

S. No. Name Range Quantity

1 Dual Power Supply (0-30)V 1

2 Resistors 1KΩ;5 KΩ;100 KΩ Each 2

3 Regulated Power Supply (0-30)V 1

4 IC µA 741 - 1

5 Voltmeter (0-50)V 1

6 Connecting Wires - -


8

CIRCUIT DIAGRAM:

NON-INVERTING AMPLIFIER: MODEL GRAPH:

DIFFERENTIAL AMPLIFIER:


9

C. THEORY:


The fundamental component of any analog computer is the operational

amplifier or op-amp and the frequency configuration in which it is used as an inverting amplifier. An

input voltage Vin is applied to the input voltage. It receives and inverts its polarity producing an

output voltage. this same output voltage is also applied to a feedback resistor Rf, which is connected to

the amplifier input analog with R1. The amplifier itself has a very high voltage gain.

If Rf = R1 then Vo=Vi

NON- INVERTING AMPLIFIER:

Although the standard op-amp configuration is as an inverting amplifier,

there are some applications where such inversion is not wanted. However, we cannot just switch the

inverting and non inverting inputs to the amplifier itself. We will still need negative feedback to

control the working gain of the circuit .Therefore, we will need to leave the resistor structure around

the op-amp intact and swap the input and ground connections to the overall circuit.

VO/VI = (Rf / Ri) +1

From the calculations, we can see that the effective voltage gain of the

non-inverting amplifier is set by the resistance ratio. Thus, if the two resistors are equal value, then the

gain will be 2 rather than 1.


A circuit that amplifies the difference between two signals is called as a

differential amplifier. This type of amplifiers is very useful in instrumentation circuits. From the

experimental setup of a differential amplifier, the voltage at the output of the operational amplifier is

zero. The inverting and non-inverting terminals are at the same potential. Such a circuit is very useful

in detecting very small differences in signals. Since the gain can be chosen to be very large. For

example, if R2=100R1, then a small difference V1-V2 is amplified 100 times.


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TABULATION:


S.No Input Voltage (in volts) Output Voltage (in volts)

1

1

−9.93

NON- INVERTING AMPLIFIER:


1

1

11.2



1

2

V1 V2

9.74

9.80

3 2

2 3


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D. PROCEDURE:

Connections are made as per the EXPERIMENTAL SETUP.

The supply is switched ON.

Output is connected to anyone channel of CRO.

The V1 and V2 voltages are fixed and measured from the other channel of CRO

and the corresponding output voltages are also noted from the CRO.

The above step is repeated for various values of V1 and V2.V1 and V2 may be

AC or DC voltages from function generator or DC power supply.

Readings are tabulated and gain was calculated and composed with designed

values.

REVIEW QUESTIONS:

1. Define an operational amplifier.

An operational amplifier is a direct-coupled, high gain amplifier consisting of one or more differential

amplifier. By properly selecting the external components, it can be used to perform a variety of

mathematical operations.

2. Mention the characteristics of an ideal op-amp.

* Open loop voltage gain is infinity. *Input impedance is infinity. *Output impedance

is zero. *Bandwidth is infinity. *Zero offset.

3. Define input offset voltage.

A small voltage applied to the input terminals to make the output voltage as zero when the two input

terminals are grounded is called input offset voltage.

4. Define input offset current.

The difference between the bias currents at the input terminals of the op-amp is called as input offset

current.

RESULT

Thus the Inverting, Non-inverting and Differential amplifier using op-amp was designed and

tested.


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CIRCUIT DIAGRAM:

DIFFERENTIATOR:

MODEL GRAPH:


13


Title of the exercise/experiment : Integrator and Differentiator


INTRODUCTION


To construct and test the performance of an Integrator and Differentiator using IC µA

741

ACQUISITION


B. DESIGN:

DIFFERENTIATOR:

Let fa = 50 Hz; C1 = 0.1μF

fa = 1 / 6.28 Rf C1

Rf = 31.8KΩ

Rf = 10R1

R1 = 3.1 KΩ

INTEGRATOR:

Let fb = 50 Hz; Cf = 0.1μF

fb = 1 / 6.28 R1 Cf

R1 = 10KΩ

Rf = 10R1

Rf = 100 KΩ



2 Resistors 31.8KΩ;3.1KΩ;10KΩ;100KΩ;

1KΩ

Each 1.

3


4 IC µA 741 - 1

5 AFO (0-1)MHz 1

6 Capacitor 0.1μF 1

7. CRO (0-20)MHz 1

8. Connecting Wires - -


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INTEGRATOR:

MODEL GRAPH:


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C. THEORY:

DIFFERENTIATOR:

Op-amps allow us to make nearly perfect integrators such as the

practical integrator the circuit incorporates a large resistor in parallel with the feedback capacitor. This

is necessary because real op-amps have a small current flowing at their input terminals called the "bias

current". This current is typically a few nanoamps, and is neglected in many circuits where the

currents of interest are in the microamp to milliamp range. The feedback resistor gives a path for the

bias current to flow. The effect of the resistor on the response is negligible at all but the lowest

frequencies.

INTEGRATOR:

One of the simplest of the operational amplifier that contains capacitor is

differential amplifier.As the suggests, the circuit performs the mathematical operation of

differentiation.the output is the derivative of the given input signal voltage.The minus sign indicates a

1800 phase shift of the output waveform Vo with respect to the input signal.


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TABULATION:

Amplitude (Volts)

Time Period (ms)

Input

3.6

1

Differentiator Output

20

1

Integrator Output

18

1


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D. PROCEDURE:

The connections are given as per the experimental setup.

The supply is switched ON after checking the circuit connections.

The input wave form is applied from the function generator and the

corresponding output waveform is noted from the CRO.

The above mentioned procedure is repeated for differentiator also.

REVIEW QUESTIONS:

1. What are the applications of current sources?

Transistor current sources are widely used in analog ICs both as biasing elements and as load

devices for amplifier stages.

2. Justify the reasons for using current sources in integrated circuits.

*superior insensitivity of circuit performance to power supply variations and temperature.

*more economical than resistors in terms of die area required to provide bias currents of small

value.

*When used as load element, the high incremental resistance of current source results in high

voltage gains at low supply voltages.

3. What is the advantage of wilder current source over constant current source?

Using constant current source output current of small magnitude (micro amp range) is not

attainable due to the limitations in chip area. Wilder current source is useful for obtaining small output

currents. Sensitivity of wilder current source is less compared to constant current source.

4.Mention the advantages of Wilson current source.

*provides high output resistance.

*offers low sensitivity to transistor base currents.

RESULT

Thus the Integrator and Differentiator using op-amp was designed and tested.


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CIRCUIT DIAGRAM:

INSTRUMENTATION AMPLIFIER

MODEL GRAPH:


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Title of the exercise/experiment : Instrumentation amplifier


INTRODUCTION


To design and verify the operation of instrumentation amplifier using IC µA 741

ACQUISITION


B

B. DESIGN:

V01 = (1+R2/R1) V1− (R2/R1) V2, V02 = (1+R2/R1) V2 − (R2/R1) V1

V0 = V02 − V01

= (V2−V1) (1+2R2/R1),

Gain = V0/Vi

= Vo / (V2−V1)

= (1+2R2/R1)

C. THEORY:

In a number of instrumentation and consumer applications one is required to

measure and control the physical quantities. Some typical examples are measurement and control of

temperature, humidity, light, Intensity, water flow etc. These physical quantities are usually measured

with the help of transducer. The output of the transducer has to be amplified so that it can derive the

indicator or display system. The functions performed by an instrumentation amplifier are,

High gain accuracy.



2 Resistors

10KΩ;

100KΩ;

120KΩ;

5

2

2


4 IC µA 741 - 3

5 AFO (0-1)MHz 1

6. CRO (0-20)MHz 1



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TABULATION:

S.NO. V1 (V) V2 (V) Vd = V2~V1 Vo (V) GAIN

1

2

3

4

5

6

7

0.01

2.35

3.43

4.02

4.50

4.75

4.99

0.02

2.62

3.81

4.49

4.99

5.3

5.51

0.01

0.27

0.38

0.47

0.49

0.55

0.52

0.03

5.28

7.70

9.07

9.98

10.62

11.10

9.25

25.82

26.13

25.71

26.17

25.71

26.58


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High CMRR.

High gain stability with low temperature coefficient.

Low dc offset.

Low input impedance.

These are specially designed op-amp such as VA725 to meet the above started

requirement of a good instrumentation amplifier. Monolithic instrumentation amplifiers are also

available commercially such as AD521, AD524, and AD624 by analog devices L40036, and L40037

by national semiconductors.

D. PROCEDURE:

Circuit connections are given as per the experimental setup.

The input signal is given.

The dual power supply is switched ON.

The input is varied in steps and the corresponding output readings are noted

from CRO.

The practical gain is calculated from the readings.

REVIEW QUESTIONS:

1. What is the need for an instrumentation amplifier?

In a number of industrial and consumer applications, the measurement of physical quantities is usually

done with the help of transducers.

2. Mention some of the linear applications of op – amps.

Adder, subtractor, voltage to current converter, current to voltage converters, instrumentation

amplifier, analog computation, power amplifier, etc are some of the linear op-amp circuits.

3. Mention some of the non – linear applications of op-amps.

Rectifier, peak detector, clipper, clamper, sample and hold circuit, log amplifier, anti–log amplifier,

multiplier are some of the non – linear op-amp circuits.

4. What are the areas of application of non-linear op- amp circuits?

Industrial instrumentation, Communication and Signal processing

RESULT

Thus the instrumentation amplifier is designed and tested using IC µA 741.


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CIRCUIT DIAGRAM:

ACTIVE LOW PASS FILTER:

MODEL GRAPH:


23


Title of the exercise/experiment : Active low pass, High pass and Band pass filters.


INTRODUCTION


To design and verify the operation of the Active low pass, High pass and Band pass

filters using IC µA 741

ACQUISITION


B

B. DESIGN:

LOW PASS & HIGH PASS:

fh = 1 / 6.28 RC

For LPF fh = 1 KHz and HPF fL = 1 KHz; Assume C = 0.1Μf

R = 1.6KΩ

A = 3 – α; where α = damping = 1.414

A = 1 + Rf / R1; Let R1 = 10KΩ

Rf = 5.8 KΩ

BAND PASS:

fc = 1KHz; AF = 10 & Q = 3

Let C1 = C2 = 0.01μF

R1 = Q / 6.28 fc C AF = 4.77KΩ

R2 = Q / 6.28 fc C (2Q2 − AF) = 5.97 KΩ

R3 = Q / 3.14 fc C = 95.5 KΩ



2 Resistors 4.7KΩ;1.2KΩ;10KΩ;6.2KΩ;100KΩ

1.5KΩ; 100Ω;

1

2

3 Capacitor 0.1μF;0.01μF 2

4 IC µA 741 - 1

5 AFO (0-1)MHz 1

6. CRO (0-20)MHz 1



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ACTIVE HIGH PASS FILTER:

MODEL GRAPH:


25

C. THEORY:

The first order low pass filter is realized RC circuit used along with an op-amp

in non-inverting configuration. A low pass filter has constant gain from) Hz to fH.. Bandwidth of this

filter is fH. Bandwidths of electric filters are used in circuits which require the separation of signals

according to their frequencies. a first order low pass filter consists of a single RC network connected

to the positive input terminal of non-inverting op-amp amplifier. Resistors Ri and Rf determine the

gain of the filter in the pass band.

The parameters in the band pass filter are lower cutoff frequency, the upper

cutoff frequency and the bandwidth, the central frequency gain Ao and selectivity Q. The higher

selectivity Q, the sharper the filter. Below 0.5fo all filters roll off at -20dB/decade independent of the

value of Q. This is limited by the two RC pair of circuits.

D. PROCEDURE:

Connections are given as per the experimental setup.

Supply is switched ON after checking the connections.

Input voltage is set to 1V and by changing the input frequency, output voltage is

measured.

The procedure is applied to active low pass; high pass and band pass filters


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CIRCUIT DIAGRAM:

BAND PASS FILTER:

MODEL GRAPH:


27


28

TABULATION:

LOW PASS FILTER:

InputVoltage Vi = 0.5

Frequency Output Voltage Gain = 20log(Vo / Vi)

400

500

600

700

800

900

1K

2K

3K

4K

6K

10K

1.2

1.2

1.2

1

1

1

1

0.4

0.2

0.2

0.1

0

7.6

7.6

7.6

6.02

6.02

6.02

6.02

−1.938

−7.95

−7.95

−13.97

0

HIGH PASS FILTER:



10

50

100

600

800

1K

2K

3K

4K

5K

6K

0.2

0.4

0.6

0.8

1

1.2

1.4

1.4

1.4

1.4

1.4

−12.04

−6.02

−2.49

0

1.93

3.52

4.86

4.86

4.86

4.86

4.86

BAND PASS FILTER:



10

30

100

200

500

1K

2K

9K

10K

20K

60K

0.2

0.3

0.7

1.3

1.8

1.9

1.9

1.9

1.6

1.2

0.6

−20

−16.47

−9.11

−3.14

−0.915

−0.44

−0.44

−0.44

−1.93

−4.43

−10.45


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REVIEW QUESTIONS:

1. Define sensitivity.

Sensitivity is defined as the percentage or fractional change in output current per percentage or

fractional change in power-supply voltage.

2. What do you mean by a precision diode?

The major limitation of ordinary diode is that it cannot rectify voltages below the cut – in voltage of

the diode. A circuit designed by placing a diode in the feedback loop of an op – amp is called the

precision diode and it is capable of rectifying input signals of the order of mill volt.

3. Write down the applications of precision diode.

Half - wave rectifier

Full - Wave rectifier

Peak – value detector

Clipper

Clamper

4. List the applications of Log amplifiers

Analog computation may require functions such as lnx, log x, sin hx etc. These functions can be

performed by log amplifiers Log amplifier can perform direct dB display on digital voltmeter and

spectrum analyzer Log amplifier can be used to compress the dynamic range of a signal

RESULT

Thus the operation of Active Low Pass Filter, High Pass Filter and Band Pass Filter was

designed and output was tested using IC µA 741.


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CIRCUIT DIAGRAM:

ASTABLE MULTIVIBRATORS:

MODEL GRAPH:


31


Title of the exercise/experiment : Astable, Monostable multivibrators and Schmitt

trigger using Op-Amp.


INTRODUCTION


To design and construct an Astable, Monostable multivibrators and Schmitt trigger

using IC µA 741

ACQUISITION


B

B. DESIGN:


Feedback factor = R2 / (R1 + R2)

T = 2RC ln[(1 + β)/(1 − β)]

Let R1 = R2 = 10KΩ then β = 0.5

Assume C = 0.1μF; for a time period of 1ms

T = 2RC ln 3

Rf = 4.55KΩ

SCHMITT TRIGGER:

Vut = (R2 / R1 + R2) Vsat ; Vlt = (R2 / R1 + R2) −Vsat

Let Vut = 0.5V; Vlt = −0.5

R1 = 27 R2 ; Let R1 = 1KΩ; R2 = 27KΩ



2 Resistors 4.5KΩ;1KΩ;27KΩ;22KΩ;5.6KΩ;760Ω

1.5KΩ; 10KΩ;

1

2

3 Capacitor 0.1μF;0.01μF 1

4 IC µA 741 - 1

5 AFO (0-1)MHz 1

6. CRO (0-20)MHz 1

7. Diode 0A79 2



32

CIRCUIT DIAGRAM:

MONOSTABLE MULTIVIBRATORS:

MODEL GRAPH:


33

C. THEORY:

ASTABLE MULTIVIBRATOR:

The astable multivibrator is also known as free running oscillator. the principle

of generation of square wave output is to force an op-amp to operate in saturation region. β = R2/

(R1+R2) of the output is feedback to the positive input terminal. the reference voltage is Vo and may

take the values as +βVsat and –βVsat. The output is also feedback to the negative input terminal after

interchanging by a low pass RC combination. Whenever input terminal just exceeds Vref switching

takes place resulting in square wave output. In this multivibrator both sates are quasi stable state

MONOSTABLE MULTIVIBRATOR:

The monostable multivibrator is also called as one shot multivibrator. The

circuit produces a single pulse of specified duration in response to each external trigger response. it is

always have one stable state. When an external trigger is applied, the output changes the state. The

new state is called quasi stable state. The circuit remains in this state for a fixed interval of time and

then it returns to the original state after this interval. This time interval is determined by the charging

and discharging of the capacitor.

SCHMITT TRIGGER:

If the positive feedback is added to the comparator circuit means gain can be

increased greatly. Consequently the transfer curve comparator becomes more close to the ideal curve

theoretically. If the loop gain βfo is adjusted to unity then the gain with feedback average becomes

extreme values of output voltage. in practical circuits, however it may not be possible to maintain loop

gain exactly equal to unity for a long time because of supply voltage and temperature variations so a

value greater than unity is chosen. This gives the output waveform virtually disconnected at the

comparison voltage. This circuit however exhibits phenomenon called hystersis or backlash.


34

CIRCUIT DIAGRAM:

SCHMITT TRIGGER:

MODEL GRAPH:


35

D. PROCEDURE:



Supply is switched ON after checking the circuit connections.

The output square wave form and the capacitor charging and discharging

waveforms are noted from the CRO.





waveforms are note down from the CRO.

SCHMITT TRIGGER:


The supply is switched ON.

The output waveform was noted from CRO and UTP and LTP are noted. The

graph is drawn.


36

TABULATION:


Amplitude (V) Time Period (ms)

Input

6

0.01

Output

11.5

TON = 0.5

TOFF = 0.5



Input

5

0.01

Output

11

TON = 0.5

TOFF = 1

SCHMITT TRIGGER:


Input

6

1

Output

11

TON = 0.5

TOFF = 0.5


37

REVIEW QUESTIONS:

1. What are the applications of comparator?

Zero crossing detectors

Window detector

Time marker generator

Phase detector

2. What is a Schmitt trigger?

Schmitt trigger is a regenerative comparator. It converts sinusoidal input into a square wave output.

The output of Schmitt trigger swings between upper and lower threshold voltages, which are the

reference voltages of the input waveform.

3. What is a multivibrator?

Multivibrators are a group of regenerative circuits that are used extensively in timing applications. It

is a wave shaping circuit which gives symmetric or asymmetric square output. It has two states stable

or quasi- stable depending on the type of multivibrator.

4. What do you mean by monostable multivibrator?

Monostable multivibrator is one which generates a single pulse of specified duration in response to

each external trigger signal. It has only one stable state. Application of a trigger causes a change to

the quasi-stable state. An external trigger signal generated due to charging and discharging of the

capacitor produces the transition to the original stable state.

RESULT

Thus the operation of Astable, Monostable multivibrators and Schmitt trigger was designed

and output was tested using IC µA 741.


38

CIRCUIT DIAGRAM:

RC PHASE SHIFT OSCILLATOR:

MODEL GRAPH:


39


Title of the exercise/experiment : RC Phase shift and Wien bridge oscillators


INTRODUCTION


To design and test RC phase shift and Wien bridge oscillators using IC µA 741.

ACQUISITION


B

B. DESIGN:

RC PHAASE SHIFT OSCILLATOR:

Given, fo = 500Hz; Assume C = 0.1µF

fo = 1/(2π√6 RC),

R = 1.3KΩ

R1 = 10R = 13KΩ

Av= − Rf / R1, Av > -29, ie, Rf/ R1 > 29

Rf = 390KΩ

Rcomp = (R1Rf / R1 + Rf) = 15KΩ

WIEN BRIDGE OSCILLATOR:

Given, fo = 10KHz; Assume C = 0.01µF

fo = 1/(2π√6 RC),

R = 1.59KΩ

R1 = 10R = 15.9KΩ

Rf = 2R1 = 31.8KΩ



2 Resistors 13KΩ;15KΩ;390KΩ;31.8KΩ;15.9KΩ;

1.5KΩ; 1.59KΩ

1

3

3 Capacitor 0.1μF;

0.01μF

3

2

4 IC µA 741 - 1

5 AFO (0-1)MHz 1

6. CRO (0-20)MHz 1



40

CIRCUIT DIAGRAM:

WEIN BRIDGE OSCILLATOR:

MODEL GRAPH:


41

C.THEORY:


RC phase shift oscillator using op-amp, in inverting amplifier mode.

Thus it introduces a phase shift of 1800 between the input and output. The feedback network consists

of 3 RC sections producing each 600 phase shift. Such a circuit is known as RC phase shift network.

The circuit is generating its own output signal and a stage of oscillator sustained. The phase shift

produced by op-amp is 1800.the op-amp with a gain of 29 and RC network is of equal resistor and

capacitor connected feedback the op-amp output and input terminals. Resistor and junctions as a last

resistor in phase shift network, give here is a phase load network produces an 1800 shift so that total

loop phase shift is 3600.


It is commonly used in audio frequency oscillator. The feedback signal

is connected in the input terminal so that the output amplifier is working as a non-inverting amplifier.

The Wien bridge circuit is connected between amplifier input terminal and output terminal. The bridge

has a series R network, in one arm and a parallel RC network in the adjoining arm. In the remaining

two arms of the bridge, resistor R1 and Rf are connected. the phase angle criterion for oscillation is

that the total phase shift around the circuit must be zero. This condition occurs when bridge is

balanced. At resonance frequency of oscillation is exactly the resonance frequency of balanced Wien

bridge and is given by f0 = 1/ (2πfC).assuming that the resistors are input impedance value and

capacitance are equal to the value in the reactive stage of Wien bridge. At this frequency, the gain

required for sustained.

D.PROCEDURE:


Circuit connections are given as per the experimental setup.

Supply is switched ON.

3600 phase shift output is obtained at the output.

The inverting op-amp produce 1800 and RC network produce another

1800.

Frequency is calculated by the formula f =1/T


42

TABULATION:


Amplitude (V)

Time Period (ms)

12.5

1


Amplitude (V)

Time Period (ms)

12

1


43



Resistor and capacitor values are verified simultaneously; the

corresponding Rf value is noted.

The critical vale of frequency is noted correspondingly.

Check whether the calculated and observed frequency values are same.

Graph is drawn by taking amplitude along y-axis and time along x-

axis.the graph will be sine waveform.

REVIEW QUESTIONS:

1. Define conversion time.

It is defined as the total time required converting an analog signal into its digital output. It depends on

the conversion technique used & the propagation delay of circuit components.

2. What is settling time?

It represents the time it takes for the output to settle within a specified band ±½LSB of its final value

following a code change at the input (usually a full scale change). It depends upon the switching time

of the logic circuitry due to internal parasitic capacitance & inductances. Settling time ranges from

100ns.10µs depending on word length & type circuit used.

3. Explain in brief stability of a converter.

The performance of converter changes with temperature age & power supply variation. So all the

relevant parameters such as offset, gain, linearity error & monotonicity must be specified over the full

temperature & power supply ranges to have better stability performances.

4. What are the problems associated with switch type phase detector?

The output voltage Ve is proportional to the input signal amplitude. This is undesirable because it

makes phase detector gain and loop gain dependent on the input signal amplitude.

RESULT

Thus the operation of RC phase shift and Wien bridge oscillators was designed and output was

tested using IC µA 741.


44

PIN DIAGRAM:

CIRCUIT DIAGRAM:


MODEL GRAPH:


45


Title of the exercise/experiment : Astable and Monostable multivibrators using NE555 Timer.


INTRODUCTION


To design and construct an Astable and Monostable multivibrators using NE555 Timer.

ACQUISITION


B

B. DESIGN:


CASE1: Given f = 1 KHz and D = 0.5

f = 1.45 / (RA + RB) C; D = RB / (RA + RB) = 0.5

RA = RB; Let C = 0.1µF; RA = RB = R

f = 1.45 /2RC; R = 7.2KΩ

CASE2: f = 1.45 / (RA + 2RB) C;D = RB / (RA + 2RB) = 0.25

RA = 2RB ; Let C = 0.1µF; RA = 2RB = 4RB

f = 1.45 / 4RBC; RB = 3.625KΩ; RA =7.25KΩ


Time Period of monostable multivibrator = 1.1RC

T = 1m/s; Assume C= 0.1µF

R = T / 1.1C

R = 10KΩ



2 Resistors 3.625KΩ;7.25KΩ;

10KΩ;

1

2

3 Capacitor 0.1μF;0.01μF;0.001µF 1

4 IC 555 - 1

5 AFO (0-1)MHz 1

6. CRO (0-20)MHz 1

7. Diode 0A79 2



46

CIRCUIT DIAGRAM:


MODEL GRAPH:


47

C. THEORY:


The astable multivibrator is also called the free running multivibrator. It has two

quasi states i.e. no stable states as such the circuit conditions oscillate between the components values

used to decide the time for which circuit remains in each stable state. the principle of square wave

output is to force the IC to operate in saturation region. Whenever input at the negative input terminal

just exceeds Vref switching takes place resulting in a square wave output. In astable multivibrator both

stable states and one quasi state are present.


These multivibrators are comprised of group of regenerative circuits that are

commonly used in timing applications. The circuit produces a single pulse of applied duration in

response to each external trigger pulse. For each circuit only one state exists. When an external trigger

is applied the output changes its state. The new state is called quasi-stable state.

D. PROCEDURE:





waveforms are noted from the CRO.





waveforms are note down from the CRO.


48

TABULATION:



Input

6

0.01

Output

11.5

TON = 0.5

TOFF = 0.5



Input

5

0.01

Output

11

TON = 0.5

TOFF = 1


49

REVIEW QUESTIONS:

1. What are the applications of comparator?

Zero crossing detectors

Window detector

Time marker generator

Phase detector

2. What is a Schmitt trigger?

Schmitt trigger is a regenerative comparator. It converts sinusoidal input into a square wave output.

The output of Schmitt trigger swings between upper and lower threshold voltages, which are the

reference voltages of the input waveform.

3. What is a multivibrator?

Multivibrators are a group of regenerative circuits that are used extensively in timing applications. It

is a wave shaping circuit which gives symmetric or asymmetric square output. It has two states stable

or quasi- stable depending on the type of multivibrator.

4. What do you mean by monostable multivibrator?

Monostable multivibrator is one which generates a single pulse of specified duration in response to

each external trigger signal. It has only one stable state. Application of a trigger causes a change to

the quasi-stable state. An external trigger signal generated due to charging and discharging of the

capacitor produces the transition to the original stable state.

RESULT

Thus the operation of Astable and Monostable multivibrators was designed and output was

tested using NE555 Timer.


50

BLOCK DIAGRAM OF NE565 PLL:

CIRCUIT DIAGRAM:


51


Title of the exercise/experiment : PLL Characteristics and Frequency multiplier.


INTRODUCTION


To design and construct a PLL Characteristics and Frequency multiplier using NE 565.

ACQUISITION


B

B. THEORY:

The block diagram of LM565 PLL consists of base detector amplifier. low pass

filter and VCO as shown in the block diagram. The phase locked loop is not connected internally. It is

necessary to connect output of VCO (pin 4) to phase comparator in pin 5 externally. in frequency

multiplication applications a digital frequency driver is inserted into loop between pin 4 and pin 5.the

centre frequency of PLL is determined by free running frequency multiplier of VCO given by free

funning frequency of VCO which is given by f0 = 1.2 / (4R1C1) Hz. the value of Ri is restricted from

2KΩ to 20KΩ but a capacitor can have any value. A capacitor C2 is connected between pin 7 and to

the Positive supply from a first order low pass filter with an external resistance of 3.6 KΩ.



2 Resistors 6.8KΩ;20KΩ;2KΩ;10KΩ;

4.7KΩ;

1

1

3 Capacitor 1μF;10μF;0.01μF;0.001µF 1

4 IC NE565 - 1

5 AFO (0-1)MHz 1

6. CRO (0-20)MHz 1

7. Transistor 2N2222 1



52

CIRCUIT DIAGRAM:

PLL AS FREQUENCY MULTIPLIER:


53

The value of filter capacitor C2 should be large enough to eliminate positive oscillator into VCO

voltage.

FL = I.8fo/V Hz.

Where, fo = free running frequency in Hz

V = +V − (−V) volts

FL = ± (fo /2π3.6x103 C2)1/2

Where, C2 is in farads

D. PROCEDURE:


Observe the waveform at pin 4 and pin 5 without any input signal. This

is free running frequency of VCO (fo).

Switch ON the functional generator and give the square waveform of

1Vpp & 1KHz. Gradually increase the fi till the PLL is locked with fi

100Hz to 4KHz and note down the FL2 and FL1 then decrease the

frequency from 4KHz to 1000Hz and note down the f3 and f1.

Calculate the capture range and lock range.


54

TABULATION:

Amplitude

Time Period

Input

Output


55

REVIEW QUESTIONS:

1. Mention some areas where PLL is widely used.

*Radar synchronisation *satellite communication systems *air borne navigational

systems *FM communication systems *Computers.

2. List the basic building blocks of PLL

*Phase detector/comparator *Low pass filter *Error amplifier *Voltage

controlled oscillator

3. What are the three stages through which PLL operates?

*Free running *Capture *Locked/ tracking

4. Define lock-in range of a PLL.

The range of frequencies over which the PLL can maintain lock with the incoming signal is called the

lock-in range or tracking range. It is expressed as a percentage of the VCO free running frequency.

RESULT

Thus the operation of PLL Characteristics and Frequency multiplier was designed and output

was tested using NE565 Timer.


56

CIRCUIT DIAGRAM:

LM 723 VOLTAGE REGULATORS:

MODEL GRAPH:


57


Title of the exercise/experiment : DC Power Supply using LM317 and LM723.


INTRODUCTION


To design and construct a DC Power Supply using LM317 and LM723.

ACQUISITION


B

B. DESIGN:

Designing an adjustable voltage regulator LM317 to satisfy the following

specifications:

Output Voltage Vo = 5 to 12V

Output Current Io = 1A

IAdj = 100 µA maximum. If we use R1 = 240Ω; then for Vo = 5V

Vo = VREF (1 + R2 / R1) + IAdjR2

R2 = 3.75 / (5.3) (10-4) = 0.71KΩ

Similarly for Vo = 12V,

12 = 1.25 (1 + R2 / 240) + (10-4) R2

R2 = 10.75 / (5.3) (10-3)

= 2.01KΩ



2 Resistors 620Ω;2.2KΩ;10KΩ;33KΩ;

3.3KΩ;240Ω

1

1

3 Capacitor 1μF;10μF;0.001µF 1

4 LM317 & LM723 - 1

5 Ammeter (0-50)mA 1

6. Voltmeter (0-20)V 1

7. Decade Resistor Box - 1



58

LM317 VOLTAGE REGULATOR:


59

C. THEORY:

The basic voltage regulator in its simplest form consists of

a) Voltage reference Vr

b) Error amplifier

c) Feedback network

d) Active series or shunt control unit.

The voltage reference generates a voltage level which is applied to the

comparator circuit, which is generally error amplifier. The second input to the error amplifier obtained

through feedback network. Generally using the potential divider, the feedback signal is derived by

sampling the output voltage. The error amplifier converts the difference between the output sample

and the reference voltage into an error signal. This error signal in turn controls the active element of

the regulator circuit, in order to compensate the changes in the output voltage. Such an active element

is generally a transistor. Error amplifier controls the series pass transistor Q2 which acts as a variable

resistor. The series pass transistor is small power transistor having about 800mW power dissipation.

The unregulated power supply source of (< 36 V d.c) is connected to collector of series pass transistor.

Transistor Q2 acts as current limiter in case of short circuit condition. It senses

drop across Rsc placed in series with regulated output voltage externally. The frequency compensation

terminal controls the frequency response of the error amplifier. The required roll-off is obtained by

connecting a small capacitor of 100pF between frequency compensation and inverting input terminals.

D. PROCEDURE:


The input voltage is given to the circuit and the output voltage slowly varies

from zero.

Then the output voltage attains the designed value and then it is irrespective of

input voltage (the output becomes constant).


60

TABULATION:

Resistance (Ω)

Current (mA)

Voltage (Volt)

200

300

400

500

1K

2K

3K

4K

5K

17.5

17.5

17.5

17.8

8

5

3

2.5

2

4

6

7.4

8.4

8.8

9.2

9.2

9.2

9.2


61

REVIEW QUESTIONS:

1. What is settling time?

It represents the time it takes for the output to settle within a specified band ±½LSB of its final value

following a code change at the input (usually a full scale change). It depends upon the switching time

of the logic circuitry due to internal parasitic capacitance & inductances. Settling time ranges from

100ns.10µs depending on word length & type circuit used.

2. Explain in brief stability of a converter:

The performance of converter changes with temperature age & power supply variation. So all the

relevant parameters such as offset, gain, linearity error & monotonicity must be specified over the full

temperature & power supply ranges to have better stability performances.

3. What is meant by linearity?

The linearity of an ADC/DAC is an important measure of its accuracy & tells us how close the

converter output is to its ideal transfer characteristics. The linearity error is usually expressed as a

fraction of LSB increment or percentage of full-scale voltage. A good converter exhibits a linearity

error of less than ±½LSB.

4. What is monotonic DAC?

A monotonic DAC is one whose analog output increases for an increase in digital input.

RESULT

Thus the operation of DC Power Supply was designed and output was tested using LM317 and

LM723.


62

SCHEMATIC DIAGRAM:

INSTRUMENTATION AMPLIFIER

WAVEFORM:


63


Title of the exercise/experiment : Instrumentation amplifier


INTRODUCTION


To simulate instrumentation amplifier circuit using PSPICE circuit simulator and to

verify the corresponding graphs plotted.

ACQUISITION

A. SOFTWARE REQUIRED:

PSPICE student’s version 9.1

B. PROCEDURE:

Draw the schematic diagram in pspice schematic editor.

Go choose the icon “set up → analysis”, for choosing proper analysis options.

Now select the option “DC sweep”.

Choose “voltage source” and complete the remaining options like start value

and end value.

Now choose the icon “set up → Examine netlist”, and if the netlist has no

errors, choose the “simulate” option which is under “setup”.

The waveform will pop up after the simulation is done.

RESULT

Thus the instrumentation amplifier circuit is simulated and the required graphs are plotted.


64

SCHEMATIC DIAGRAM:


WAVE FORM:


65


Title of the exercise/experiment : Active low pass, High pass and Band pass filters.


INTRODUCTION


To simulate Active low pass, High pass and Band pass filters using PSPICE circuit

simulator and to verify the corresponding graphs plotted.

ACQUISITION



B. PROCEDURE:




Now select the option “AC sweep”.

Choose “Decade” for graph type and complete the remaining options like start

value and end value.





66

SCHEMATIC DIAGRAM:


WAVE FORM:


67










ACTIVE BAND PASS FILTER:










68

SCHEMATIC DIAGRAM:

BAND PASS FILTER:

MODEL GRAPH:


69

RESULT

Thus the Active low pass, High pass and Band pass filters is simulated and the required graphs

are plotted.


70

SCHEMATIC DIAGRAM:


WAVE FORM:


71


Title of the exercise/experiment : Astable, Monostable multivibrators and Schmitt

trigger using Op-Amp.


INTRODUCTION


To simulate Astable, Monostable multivibrators and Schmitt trigger using PSPICE circuit

simulator and to verify the corresponding graphs plotted.

ACQUISITION



B. PROCEDURE:




Now select the option “transient”.

Choose appropriate print step and final time.



The waveform window will pop up after the simulation is done.


72

CIRCUIT DIAGRAM:


MODEL GRAPH:


73









SCHMITT TRIGGER:









74

SCHEMATIC DIAGRAM:

SCHMITT TRIGGER:

WAVE FORM:


75

RESULT

Thus the Astable, Monostable multivibrators and Schmitt trigger is simulated and the required

graphs are plotted.


76

SCHEMATIC DIAGRAM:


WAVE FORM:


77


Title of the exercise/experiment : RC Phase shift and Wien bridge oscillators


INTRODUCTION


To simulate RC Phase shift and Wien bridge oscillators using PSPICE circuit simulator

and to verify the corresponding graphs plotted.

ACQUISITION



B. PROCEDURE:










78

SCHEMATIC DIAGRAM:


WAVE FORM:


79









RESULT

Thus the RC Phase shift and Wien bridge oscillators is simulated and the required graphs are

plotted.


80

SCHEMATIC DIAGRAM:


WAVE FORM:


81


Title of the exercise/experiment : Astable multivibrator using NE555 Timer.


INTRODUCTION


To simulate Astable multivibrator using PSPICE circuit simulator and to verify the

corresponding graphs plotted.

ACQUISITION



B. PROCEDURE:









RESULT

Thus the Astable multivibrator is simulated and the required graphs are plotted.

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