ec-ii lab manual
DESCRIPTION
Ec-II Lab ManualTRANSCRIPT
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Dr.NNCE ECE / IV SEM EC II & S LAB - LM
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EC 2257- ELECTRONIC CIRCUITS II AND SIMULATION LAB
LABORATORY MANUAL
FOR FOURTH SEMESTER B.E (ECE)
(PRIVATE CIRCULATION ONLY)
ACADEMIC YEAR 2013-2014
ANNA UNIVERSITY,CHENNAI-600025
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
DR.NAVALAR NEDUNCHEZHIYAN COLLEGE OF ENGINEERING,
THOLUDUR 606 303, CUDDALORE DIST.
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UNIVERSITY PRACTICAL EXAMINATION
Allotment of Marks
Internal assessment = 20 marks
Practical examination = 80 marks
----------------------
Total = 100 marks
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INTERNAL ASSESSMENT (20 MARKS)
Staff should maintain the assessment register and the Head of the Department should
monitor it.
Split up of internal marks
Record = 10 marks
Model exam = 5 marks
Attendance = 5 marks
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Total = 20 marks
----------------------
UNIVERSITY EXAMINATION
The exam will be conducted for 100 marks. Then the marks will be calculated to 80
marks
Split up of practical examination marks
Aim and Procedure = 25 marks
Program = 30 marks
Execution = 30 marks
Result = 05 marks
Viva voce = 10 marks
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Total = 100 marks
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GENERAL INSTRUCTIONS FOR LABORATORY CLASSES
o Enter the Lab with CLOSED FOOTWEAR.
o Boys should TUCK IN the shirts.
o Students should wear uniform only.
o LONG HAIR should be protected, let it not be loose especially near ROTATING
MACHINERY.
o Any other machines / equipments should not be operated other than the
prescribed one for that day.
o POWER SUPPLY to your test table should be obtained only through the LAB
TECHNICIAN.
o Do not LEAN and do not be CLOSE to the rotating components.
o TOOLS, APPARATUS and GUAGE sets are to be returned before leaving the
lab.
o HEADINGS and DETAILS should be neatly written
i. Aim of the experiment
ii. Apparatus / Tools / Instruments required
iii. Procedure / Theory / Algorithm / Program
iv. Model Calculations
v. Neat Diagram / Flow charts
vi. Specifications / Designs Details
vii. Tabulations
viii. Graph
ix. Result / discussions .
o Before doing the experiment, the student should get the Circuit / Program
approval by the FACULTY - IN - CHARGE.
o Experiment date should be written in the appropriate place.
o After completing the experiment, the answer to the viva-voce questions should be
neatly written in the workbook.
o Be PATIENT, STEADY, SYSTEMATIC AND REGULAR.
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LIST OF EXPERIMENTS
DESIGN OF THE FOLLOWING CIRCUITS
1. Series and shunt feedback amplifiers:
Frequency response, input and output impedance calculation
2. RC phase shift oscillator, Wien bridge oscillator
3. Hartley oscillator, Colpitts oscillator
4. Tuned class C amplifier
5. Integrators, Differentiators, Clippers and Clampers
6. Astable, Monostable and Bistable multivibrators
SIMULATION USING PSPICE
1. Differential amplifier
2. Active filters : Butterworth 2 nd order LPF, HPF (Magnitude and Phase response)
3. Astable, Monostable and Bistable multivibrator - Transistor bias
4. D/A and A/D converters (Successive approximation)
5. Analog multiplier
6. CMOS inverter, NAND and NOR
Total: 45
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CONTENTS
S.NO LIST OF EXPERIMENTS
Pa
ge
No
01 RC PHASE SHIFT OSCILLATOR 6
02 WEIN BRIDGE OSCILLATOR 9
03 COLPITTS OSCILLATOR 12
04 HARTLEY OSCILLATOR 15
05 ASTABLE MULTIVIBRATOR 18
06 MONOSTABLE MULTIVIBRATOR 21
07 BISTABLEMULTIVIBRATOR 24
08 CLASS C SINGLE TUNED AMPLIFIER 27
09 CURRENT SERIES FEEDBACK AMPLIFIER 30
10 VOLTAGE SERIES FEEDBACK AMPLIFIER 33
11 SECOND ORDER LOW PASS BUTTERWORTH FILTER
36
12 DIFFERENTIATOR SINE WAVE INPUT 39
13 DIFFERENTIATOR SQUARE WAVE INPUT 42
14 ASTABLE MULTIVIBRATOR SYMMETRICAL
45
15 ASTABLE MULTIVIBRATOR ASYMMETRICAL
48
16 MONOSTABLE MULTIVIBRATOR 51
17 BISTABLE MULTIVIBRATOR 54
18 CMOS INVERTER 57
19 CMOS NOR 60
20 CMOS NAND 63
21 DIGITAL TO ANALOG CONVERTER 66
BEYOND THE SYLLABUS
22 Inverting, Non-Inverting , Differential Amplifiers 67
23 Differential Amplifier Using BJT
24 Class B Complementary Symmetry Power Amplifier
25 Cascade Amplifier
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Exercise Number : 1
Title of the Exercise : RC PHASE SHIFT OSCILLATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To design a RC phase shift oscillator and to observe its output waveform.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S.NO APPARATUS SPECIFICATION QUANTITY
1. OPAMP IC74 1
2. Resistors 1.2K, 13K,377,12.5K
3,Each1
3. Capacitors 0.1F 3
4. RPS 12V 1
5 CRO 1MHz 1
6. Connecting wires - Req.
b) DESIGN PROCEDURE:
Frequency of oscillator F=1//2RC.
Assume C and find R to prevent loading of the amplifier by RC networkR110R.
c) 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 60. 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.
d) PROCEDURE:
Hook up the circuit as shown in the circuit diagram.
Switch on the power supply.
Observe the output waveform in CRO.
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e) CIRCUIT DIAGRAM:
f) MODEL GRAPH:
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g) TABULATION:
Amplitude(Volts) Time(ms) Frequency (KHz)
RESULT:
Thus the RC phase shift oscillator was designed and its output waveform was verified.
VIVA QUESTIONS:
1. What is amplifier? Amplifier is a device which is used to amplification purpose.
2. What is amplification? A low strength signal is converted into strengthen signal ie) boost up process
3. List the disadvantages of Rc phase shift Oscillator. (or) What are the merits of Rc phase shift Oscillator.
i. It is ideal for frequency adjustment over a wide range.
ii. It requires a high transistor to overcome losses in the network. 4. What is the difference between amplifier and oscillator/ Amplifier is working in the negative feedback while oscillator working in the positive
feedback.
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Exercise Number : 2
Title of the Exercise : WEIN BRIDGE OSCILLATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To design a wein bridge oscillator and to observe its output waveform.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S.NO APPARATUS SPECIFICATION QUANTITY
1. OPAMP IC741 1
2. Resistors 1.5K, 1K,500,1.5K
Each1
3. Capacitors 0.1F 1
4. RPS 12V 1
5 CRO 1MHz 1
6. Connecting wires - Req.
b) 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.
c) DESIGN PROCEDURE:
Select approximate transistor and note down its specification such as
Vce,Vcc(max),hoe(min) and hfe(max) and Vbe(sat). Vcc=VCEQ+ICQ(RC+RE)
Assuming appropriate stability factor and hence I2 flowing through the biasing resistor and
differentiator. Determine R1 and R2.
Using the condition for sustained oscillation R3>2R4, compute C for designed frequency for
the frequency of oscillator.
F=1/2RC
d) PROCEDURE:
Hook up the circuit as shown in the circuit diagram.
Switch on the power supply.
Observe the output waveform in CRO.
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e) CIRCUIT DIAGRAM:
f) MODEL GRAPH:
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g) TABULATION:
Amplitude(Volts) Time(ms) Frequency (KHz)
h) RESULT: Thus the Wein bridge oscillator was designed and its output waveform was verified.
VIVA QUESTIONS:
1. What is an Oscillator? An Oscillator is a Circuit, which generates an alternating voltage of any desired
frequency. It can generate an a.c output signal without requiring any externally applied input
signal.
2. What is a beat frequency oscillator? Beat frequency Oscillator (BFO) is an Oscillator in which a deserved signal frequency
such as the beat frequency produced by combining the different signal frequencies such as on
different radio frequencies.
3. What is sustained Oscillation? The electrical oscillations in which amplitude does not change with time are called as
sustained oscillations. It is also called as Undamped Oscillation.
4. What is meant by resonant Circuit Oscillators? LC Oscillators are known as resonant circuit oscillator because the frequency
of operation of LC Oscillator is nothing but a resonant frequency of tank circuit or LC tank
circuit produces sustained Oscillation at the resonant circuit oscillator.
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Exercise Number : 3
Title of the Exercise : COLPITTS OSCILLATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To design a Colpitts oscillator and to observe its output waveform.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S.NO APPARATUS SPECIFICATION QUANTITY
1. Transistor BC 107 1
2. Resistors 11.64 K, 552.2,10.02K1.67k
Each 1
3. Capacitors 53.5nF,80F, 100mF 2,1,1
4. Inductor 0.78mH 1
5. RPS 12V 1
6. CRO 1MHz 1
7. Connecting wires - Req.
b) DESIGN PROCEDURE:
Select a appropriate transistor and note down its specification such as VCE,IC(MAX), hfe(min) and
Vbe(sat).
VCC= VCEQ
R2=S* RE
VCC[R2/( R1+ R2)= VBE+VBE(SAT)
VR1+VR2=VCC
hfe C1* C2/( C1+ C1)
XCE RE/10
PROCEDURE:
Hook up the circuit as shown in the circuit diagram.
Switch on the power supply.
Slight modification in value of C1 and C2 can be made to get perfect sine wave output.
Observe the output waveform in CRO.
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c) CIRCUIT DIAGRAM: COLPITTS OSCILLATOR
d) MODEL GRAPH:
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e) TABULATION:
Amplitude(Volts) Time(ms) Frequency (KHz)
f) RESULT: Thus the Colpitts oscillator was designed and its output waveform was verified.
VIVA QUESTIONS:
1. What is piezo electric effect? The piezo electric Crystals exhibit a property that if a mechanical stress is
applied across one face the electric potential is developed across opposite face. The inverse
is also live. This phenomenon is called piezo electric effect.
2. List the disadvantages of crystal Oscillator. It is suitable for only low power circuits
Large amplitude of vibrations may crack the crystal.
It large in frequency is only possible replacing the crystal with another one by
different frequency.
3. What are parasitic Oscillators? In a practical amplifier circuit due to stray capacitances and lead inductances,
oscillations result, since the circuit conditions satisfy the Barkhavsens criterion. These Oscillators are called as unwanted or parasitic Oscillations
4. What is damped Oscillation? The electrical Oscillations in which the amplitude decreases with time are called as
damped Oscillation.
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Exercise Number : 4
Title of the Exercise : HARTLEY OSCILLATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To design a Hartley oscillator and to observe its output waveform.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S.NO APPARATUS SPECIFICATION QUANTITY
1. Transistor BC 107 1
2. Resistors 2.74 K, 1.76K,10.58K
1,2,1
3. Capacitors 0.1F, 0.1F Each 2
4. Inductor 0.1mH,0.33mH Each 1
5. RPS 12V 1
6. CRO 1MHz 1
7. Connecting wires - Req.
b) DESIGN PROCEDURE:
Select a appropriate transistor and note down its specification such as VCE,IC(MAX), hfe(max) and
Vbe(sat).
VCC= VCEQ+ ICQ(RC+RE)
R2=S* RE
VCC[R2/( R1+ R2)= VBE+VBE(SAT)
VR1+VR2=VCC
c) PROCEDURE:
Hook up the circuit as shown in the circuit diagram.
Switch on the power supply.
Slight modification in value of L1 and L2 can be made to get perfect sinewave output.
Observe the output waveform in CRO.
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d) CIRCUIT DIAGRAM: HARTLEY OSCILLATOR
e) MODEL GRAPH:
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f) TABULATION:
Amplitude(Volts) Time(ms) Frequency (KHz)
g) RESULT: Thus the Hartley oscillator was designed and its output waveform was verified.
VIVA QUESTIONS:
1. What are the types of sinusoidal oscillator? Mention the different types of sinusoidal oscillator?
RC phase shift Oscillator.
Wein bridge Oscillator.
Hartley Oscillator
Colpitts Oscillator
Crystal Oscillator
2. What is Barkhausan criterion? The conditions for oscillator to produce oscillation is given by Barkhausan
criterion. They are :
(i). The total phase shift produced by the circuit should be 360o or 0o
(ii).The Magnitude of loop gain must be greater than or equal to 1
i.e. . A 1.
3. Name two high frequency Oscillators. i. Hartley Oscillator
ii. Colpitts Oscillator
iii.Crystal Oscillator
4. What are the essential parts of an Oscillator? i. Tank circuit (or) Oscillatory circuit.
ii. Amplifier (Transistor amplifier)
iii. Feedback Circuit.
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Exercise Number : 5
Title of the Exercise : ASTABLE MULTIVIBRATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To test astable multivibrator and to observe the two quasi-stable states.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S. NO. COMPONENTS RANGE QUANTITY
1 Breadboard - 1
2 Resistors 100k, 2k 2each
3 Capacitors 0.01F 2
4 Transistor BC107 1
5 CRO 0-30MHz 1
6 RPS 0-30V 1
b) THEORY: Astable multivibrator consists of two common emitter amplifying stages.When the d.
c. power supply is switched ON (t=0) one of the transistor will start conducting more than the
other due to some imbalance in circuit. Then because of the other due to some positive
feedback, the transistor Q1 will be driven into saturation and Q2 to cut off. Thus at t>0 Q1 is
ON and Q2 is OFF. During t>0, capacitor C1 is charging and VB2 increases. As it increases
above cut-in-voltage, Q2 starts conducting at t>t1. As the transistor Q2 goes into saturation,
VC falls to VCE(sat). Thus at t>t1, Q1 is OFF and Q2 is ON. During t>t1, VB1 rises
exponentially with time constant. At T=t2, VB1 reaches cutin level and a reverse transition
take place. It is used to generate square waveform.
c) PROCEDURE: 1. The components are connected as per the circuit diagram. 2. The DC supply is switched ON. 3. The output voltage and the time period is measured across transistors T1 and T2 at both the base and the collector.
4. The output wave is plotted in the graph.
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d) CIRCUIT DIAGRAM: ASTABLE MULTIVIBRATOR
e) MODEL GRAPH:
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f) TABULATION:
Amplitude(Volts) Time(ms) Frequency (KHz)
g) RESULT:
Thus the Astable multivibrator was designed and its output waveform was verified.
VIVA QUESTIONS:
1. What is a linear waveform-shaping circuit? The process by which the shape of a nonsinusoidal signal is changed by passing the
signal through the network consisting of linear elements is called Linear Wave Shaping.
2. What is meant by multivibrator? Multivibrators are two stage switching circuits in which the output of the first stage is
fed to the input of the second state and vice-versa. The outputs of two stages are
complementary.
3. Define Astable multivibrator. Astable multivibrator is a multivibrator in which neither state is stable. There are two
temporary states. The circuit changes state continuously from one quasi stables state to
another at regular intervals without any triggering. This generates continuous square
waveform without any external signal.
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Exercise Number : 6
Title of the Exercise : MONOSTABLE MULTIVIBRATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To test a monostable multivibrator and to observe the two quasi-stable states. FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S. NO. COMPONENTS RANGE QUANTITY
1 Breadboard - 1
2 Resistors 3k, 1k, 280k, 22k,
1.75k
1 each
3 Capacitors 1nF 2
4 Transistor BC107 1
5 Diode 1N4007 1
6 CRO 0-30MHz 1
7 RPS 0-30V 1
b) THEORY: Monostble multivibrator is also called as one shot or univibrator and can be used to
generate a gating pulse, whose width can be controlled. The monostable multivibrator
provides a single pulse of desired duration in response to an external trigger. The external
trigger causes the circuit to go to the quasi stable state. After a certain interval of time, the
circuit returns to its original state. It consists of two NPN transistors. In this case, when a
pulse is applied to the input circuit, the circuit state is changed abruptly to unstable state for a
determined time after which the circuit returned to its original state automatically. The two
outputs are the complement of each other i.e when one of the output is at VCC level, the
other is at VCE(sat) level. The monostable multivibrators are used for the generation of well
defined pulses, the logic design of pulse delay, variable pulse width, etc. The width or
duration of the pulse obtained at the collector or output of either transistor of the monostable
multivibrator is given by the expression t=0.69 RC.
c) PROCEDURE:
1. The components are connected as per the circuit diagram. 2. The output is measured at the collector terminals of the two transistors. 3. The required output voltages and the total time period is noted. 4. The output wave is plotted in the graph.
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d) CIRCUIT DIAGRAM: MONOSTABLE MULTIVIBRATOR
e) TRIGGER GENERATION:
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f) TABULATION:
Amplitude(Volts) Time(ms) Frequency (KHz)
g) RESULT:
Thus the Monostable multivibrator was designed and its output waveform was
verified.
VIVA QUESTIONS:
1. Define monostable multivibrator. When a trigger pulse is applied to the input circuit, the circuit state is changed
abruptly to unstable state for a predetermined time after which the circuit returned to its
original stable state automatically.
2. Define integrator. Integrator is a circuit that passes low frequencies of the input and attenuates high
frequencies. Integrator implies that the output voltage is an integral of the input voltage.
3. What is the use of commutating capacitors? The Commutating capacitors can be used to reduce the transition time in a low to
high level and vice versa.
4. Define transition time. The time interval during which the conduction transfer from one transistor to another
transistor is defined as transition time.
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Exercise Number : 7
Title of the Exercise : BISTABLE MULTIVIBRATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To test a Bistable multivibrator and to observe the two quasi-stable states.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S. NO. COMPONENTS RANGE QUANTITY
1 Breadboard - 1
2 Resistors 3k, 1k, 280k, 22k,
1.75k
1 each
3 Capacitors 1nF 2
4 Transistor BC107 1
5 Diode 1N4007 1
6 CRO 0-30MHz 1
7 RPS 0-30V 1
b) THEORY: Bistble multivibrator is also called as one shot or univibrator and can be used to
generate a gating pulse, whose width can be controlled. The bistable multivibrator provides a
single pulse of desired duration in response to an external trigger. The external trigger causes
the circuit to go to the quasi stable state. After a certain interval of time, the circuit returns to
its original state. It consists of two NPN transistors. In this case, when a pulse is applied to
the input circuit, the circuit state is changed abruptly to unstable state for a determined time
after which the circuit returned to its original state automatically. The two outputs are the
complement of each other i.e when one of the output is at VCC level, the other is at VCE(sat)
level. The bistable multivibrators are used for the generation of well defined pulses, the logic
design of pulse delay, variable pulse width, etc. The width or duration of the pulse obtained at
the collector or output of either transistor of the bistable multivibrator is given by the
expression t=0.69 RC.
c) PROCEDURE: 1. The components are connected as per the circuit diagram. 2. The output is measured at the collector terminals of the two transistors. 3. The required output voltages and the total time period is noted. 4. The output wave is plotted in the graph.
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d) CIRCUIT DIAGRAM: BISTABLEMULTIVIBRATOR
e) MODEL GRAPH:
Output Vb1
V
Time (s)
Output Vb2 Vbe(sat)
Output Vc2
Vce(sat)
Vbe(sat)
Vce(sat)
Output Vc1
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f) RESULT: Thus the Bistable multivibrator was designed and its output waveform was verified.
VIVA QUESTIONS:
1. Define the Bistable multivibrator. Bistable multivibrator signifies a circuit which can exist indefinitely in either of two
stable states and which can be induced to make an abrupt transition from one state to other by
applying an external triggering signal.
2. Define resolving time. It is the minimum time interval between two consecutive trigger pulses and equals to
transition time plus the settling time.
3. What is meant by linear wave shaping circuit? The action of a linear network in producing a waveform at its outputs different from
its output is known as linear wave shaping circuit.
4. What are different types of triggering of bistable multivibrator? Asymmetrical triggering.
Symmetrical triggering.
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Exercise Number : 8
Title of the Exercise : CLASS C SINGLE TUNED AMPLIFIER
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To design and find the frequency response of class c single tuned amplifier.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S. NO. COMPONENTS RANGE QUANTITY
1 Breadboard - 1
2 Resistors 1k,4.7k,10k 1 each
3 Capacitors 1nF,0.01mF,0.1 mF 2
4 Transistor BC107 1
5 CRO 0-30MHz 1
6 RPS 0-30V 1
b) THEORY: In class C amplifier, the output current flows only for one half of the cycle of the input signal. The transistor dissipates no power with zero input signal. The average current
drawn by the circuit in class C is smaller than that in class A. Complementary symmetry
amplifier requireds neither an input nor an output transformer. This arrangement uses
transistors having complementary symmetry in the emitter follower configuration. The term
complementary means that it uses two identical transistors one NPN and the other PNP. The term symmetry means that biasing resistors are equal. This amplifier circuit has a unity gain because of the emitter follower configuration. Moreover there is no phase inversion of the
output signal. The split supply used in the circuit gives us an advantage that the dc
component of the output voltage can be made zero. Thus the only ac component of the power
is available across the load resistor.
c) PROCEDURE:
1. The components are connected as shown in the circuit diagram.
2. The input voltage is given using function generator.
3. The load resistance is varied using the decade resistance box and output voltage is measured and readings are tabulated
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d) CIRCUIT DIAGRAM: CLASS C SINGLE TUNED AMPLIFIER
e) MODEL GRAPH:
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f) TABULATION:
Sl.
No.
Input
frequency
(Hz)
Input
Voltage
(mV)
Output
Voltage
(V)
Voltage gain
20log ogaini
VV db
V
g) RESULT:
Thus the Class C single tuned amplifier was designed and its frequency response was
observed
VIVA QUESTIONS:
1. What is meant by tuned amplifiers? Tuned amplifiers are amplifiers that are designed to reject a certain range of
frequencies below a lower cut off frequency L and above a upper cut off frequency H and allows only a narrow band of frequencies.
2. Classify tuned amplifiers. 1.Single tuned amplifier.
2.Double tuned amplifier.
3.Synchronously tuned amplifier.
4.Stagger tuned amplifier.
3. What are the advantages of double tuned amplifier? In double tuned amplifiers, the tuning is done both at the primary and
secondary.
The double tuned amplifiers provide a wider bandwidth, flatter pass band and
a greater selectivity.
4. What is the other name for tuned amplifier? Tuned amplifiers used for amplifying narrow band of frequencies hence it is also
known as narrow band amplifier or Band pass amplifier.
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Exercise Number : 9
Title of the Exercise : CURRENT SERIES FEEDBACK AMPLIFIER
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To design and find the frequency response of current series feedback amplifier.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S. NO. COMPONENTS RANGE QUANTITY
1 Breadboard - 1
2 Resistors 10k, 11k, 200, 283
1each
3 Capacitors 1F 10F
2
1
4 Transistor BC107
5 CRO 0-30MHz 1
6 RPS 0-10V 1
7 Digital multimeter 1
b) THEORY: In the current series amplifier, the output current flows only for one half of the cycle of the input signal. The transistor dissipates no power with zero input signal.. Complementary
symmetry amplifier requires neither an input nor an output transformer. This arrangement
uses transistors having complementary symmetry in the emitter follower configuration. This
amplifier circuit has a unity gain because of the emitter follower configuration. Moreover
there is no phase inversion of the output signal. The split supply used in the circuit gives us
an advantage that the dc component of the output voltage can be made zero. Thus the only ac
component of the power is available across the load resistor.
c) PROCEDURE:
1. The components are connected as shown in the circuit diagram.
2. The input voltage is given using function generator.
3. The load resistance is varied using the decade resistance box and output voltage is measured and readings are tabulated.
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d) CIRCUIT DIAGRAM: CURRENT SERIES FEEDBACK AMPLIFIER
e) MODEL GRAPH:
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f) TABULATION:
Sl. No. Input
frequency
(Hz)
Input
Voltage (mV)
Output
Voltage (V)
Voltage gain
20log ogaini
VV db
V
g) RESULT: Thus the Current series feedback amplifier was designed and its frequency response was
observed.
VIVA QUESTIONS:
1. What is feedback amplifier? The part of the output is given to the input of the circuit called as feedback amplifier.
2. Classify the feedback amplifiers. 1) Voltage series feedback amplifier
2) Current series feedback amplifier
3) Voltage shunt feedback amplifier
4) Current shunt feedback amplifier
3. What is meant by neutralization? It is the process by which feedback can be cancelled by introducing a current that is
equal in magnitude but 180o out of phase with the feedback signal at the input of the active
device. The two signals will cancel and the effect of feedback will be eliminated. This
technique is termed as neutralization.
4. What is the application of tuned amplifiers? The application of tuned amplifiers to obtain a desired frequwnct and rejecting all other
frequency in
(i). Radio and T .V broadcasting as tunning circuit.
(ii). Wireless communication system.
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33
Exercise Number : 10
Title of the Exercise : VOLTAGE SERIES FEEDBACK AMPLIFIER
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To design and find the frequency response of voltage series feedback amplifier.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
S. NO. COMPONENTS RANGE QUANTITY
1 Breadboard - 1
2 Resistors 10k, 11k, 200, 283
1each
3 Capacitors 1F 10F
2
1
4 Transistor BC107
5 CRO 0-30MHz 1
6 RPS 0-10V 1
7 Digital multimeter 1
b) THEORY:
The feedback voltage is connected in series with the input circuit means called as
voltage series amplifier. If the feedback voltage is equal to the output voltage then it is called
as voltage series feedback amplifier.
c) PROCEDURE:
1. The components are connected as shown in the circuit diagram.
2. The input voltage is given using function generator.
3. The load resistance is varied using the decade resistance box and output voltage is measured and readings are tabulated.
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d) CIRCUIT DIAGRAM: VOLTAGE SERIES FEEDBACK AMPLIFIER
e) MODEL GRAPH:
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f) TABULATION:
Sl. No. Input
frequency
(Hz)
Input
Voltage
(mV)
Output
Voltage (V)
Voltage gain
20log ogaini
VV db
V
g) RESULT: Thus the Current series feedback amplifier was designed and its frequency response was
observed.
VIVA QUESTIONS:
1.List out the types of feedback circuits.
Positive feedback
Negative feedback
2.Write the advantages of negative feedback.
Higher input and lower output impedance.
Improved higher sensitivity
Reduced noise
Increased bandwidth
Reduced distortion
3.Write the disadvantages of negative feedback
reduced overall circuit gain
reduced distortion
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36
Exercise Number : 11
Title of the Exercise : SECOND ORDER LOW PASS BUTTERWORTH FILTER
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the frequency response of second order low pass filter by using
ORCAD capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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c) CIRCUIT DIAGRAM: SECOND ORDER LOW PASS BUTTERWORTH FILTER
d) MODEL GRAPH:
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e) RESULT: Thus the second order low pass filter circuit was simulated using ORCAD capture and
its frequency response was obtained.
VIVA QUESTIONS:
1. Write the equation for finding the bandwidth. Bandwidth= f2-f1
Where f1= lower cut off frequency and f2= higher cut off frequency
2. What is blocking oscillator? The circuit which uses a regerative feedback, producing a single pulse or pulse
train is called a blocking oscillator.
3. Which are the two important elements of a blocking oscillator? 1. Active element like transistor.
2. A pulse transformer.
4. What is pulse transformer? A pulse transformer is basically a transformer which couples a source of pulses of
electrical energy to the load, keeping the shape and other properties of pulses unchanged. The
voltage level of the pulse can be raised or lowered by designing the proper turns ratio for the
pulse transformer.
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39
Exercise Number : 12
Title of the Exercise : DIFFERENTIATOR SINE WAVE INPUT
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of differentiator circuit by using ORCAD
capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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c) CIRCUIT DIAGRAM: DIFFERENTIATOR SINE WAVE INPUT
d) MODEL GRAPH:
:
Amplitude
in volts
0
Time in ms
0
Time in ms
0
0
0 0
AD741 3
2
7
4
6
1
5 +
-
V+
V-
OUT
OS1
OS2
1.59k
15.9k
1.44k
0.01u
0.1u
12v
12v
C2
R2
R1 C1
R3
OUTPUT
INPUT
Frequency=100
AC=1
DC=0
Voff=0
Vamp=1V
Maximum Step Size= 0.2us
Analysis Type : Time Domain ( Transient) Run to Time =40ms
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41
e) RESULT: Thus the Differentiated Sine wave input circuit was simulated using ORCAD capture
and its frequency response was obtained.
VIVA QUESTIONS:
1. Define differentiator. Differentiator is a circuit that passes high frequencies of the input and attenuates low
frequencies. It implies that the output voltage is the differential of the input.
2. What is meant by clippers? The circuit with which the waveform is shaped by removing a portion of the input
signal without distorting the removing part of the alternating waveform is called a clipper.
3. What is meant by clampers? Clamping network shifts (clamp) a signal to a different d.c level, i.e., it introduces a
d.c level to an a.c signal.Hence,the clamping network is known as d.c restorer.
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Dr.NNCE ECE / IV SEM EC II & S LAB - LM
42
Exercise Number : 13
Title of the Exercise : DIFFERENTIATOR SQUARE WAVE INPUT
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of differentiator circuit by using ORCAD
capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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CIRCUIT DIAGRAM: DIFFERENTIATOR - SQUARE WAVE INPUT
c) MODEL GRAPH:
0
0
0 0
1.59k AD741 3
2
7
4
6
1
5 +
-
V+
V-
OUT
OS1
OS2
12v
12v
0.1u
0.01u
1.44k
15.9k
C2
R2
R1 C1
R3
OUTPUT
INPUT
V1= -1V V2= 1V AC=10 DC=0 TR=0ms TF=0ms TD=0ms PW=5ms PER=0.01s
Analysis Type : Time Domain ( Transiant) Run to Time =20ms
Maximum Step Size= 0.2us
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44
d) RESULT: Thus the Differentiated Square wave input circuit was simulated using ORCAD
capture and its frequency response was obtained.
VIVA QUESTIONS:
1. What is delay time? The time required for the current to rise to 10% of its maximum (saturation) value Ics
is called the delay time td.
2. What is the total turn on time? The total turn on time is ton is the sum of the delay time and rise time,
ton = td + tr
Where,
td = Delay time.
tr = Rise time.
3. What is storage time? The interval that elapses between the transition of the input waveform and the time
when the collector current has dropped to 90 % of total output is called the storage time ts.
4. Define transition time. The time interval during which the conduction transfer from one transistor to another
transistor is defined as transition time.
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Dr.NNCE ECE / IV SEM EC II & S LAB - LM
45
Exercise Number : 14
Title of the Exercise : ASTABLE MULTIVIBRATOR SYMMETRICAL
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of astable multivibrator(symmetrical) by using
ORCAD capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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46
c) CIRCUIT DIAGRAM: ASTABLE MULTIVIBRATOR SYMMETRICAL
d) MODEL GRAPH:
Vce(sat) V
Vce(sat)
Vbe(sat)
Vbe(sat)
Time(s)
Output Vc2
Output Vc1
Output Vb2
Output Vb1
0 0
0
C1
0.01U
1k 36K 1k
SMBT2222A/SIE SMBT2222A/SIE
C2
0.01U
36K
8V
Analysis type: Time domain transient Run to time: 5ms Maximum step size: 0.2us
V1
Rc1 R2 R1 Rc2
Vc1 Vc2
Vb2 Vb1 Q23 Q22
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47
e) RESULT: Thus the astable multivibrator(symmetrical) circuit was simulated using ORCAD
capture and its output waveform was obtained.
VIVA QUESTIONS:
1. What is Leading edge response? At start there is an overshoot and then the pulse settles down. The response till it settles
down after the overshoot is called leading edge response.
2. What is trailing edge response? The response generally extends below the zero amplitude after the end of pulse width
is called back swing. The portion of response from backswing till it settes down is trailing
edge response.
3. What is flat top response? The portion of the response between the trailing edge and the leading edge is called
flat top response.
4. Define rise time of a pulse. The rise time is an important parameter related to this part of the response.It is defined
by the time required by the pulse to rise from 10 % of its amplitude to 90 % of its amplitude.
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48
Exercise Number : 15
Title of the Exercise : ASTABLE MULTIVIBRATOR ASYMMETRICAL
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of astable multivibrator(Asymmetrical) by using
ORCAD capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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49
c) CIRCUIT DIAGRAM: ASTABLE MULTIVIBRATOR- ASYMMETRICAL
d) MODEL GRAPH:
Vce(sat)
V
Vce(sat)
Vbe(sat)
Vbe(sat)
Time(s)
Output Vc2
Output Vc1
Output Vb2
Output Vb1
0 0
0
43K 1k
C1
0.01U
C2
0.01U
28K
8V
SMBT2222A/SIE SMBT2222A/SIE
1k
Analysis type: Time domain transient
V1
Rc1 R2 R1 Rc2
Vc1 Vc2
Vb2 Vb1 Q23 Q22
Run to time: 5ms Maximum step size: 0.2us
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e) RESULT: Thus the astable multivibrator(asymmetrical) circuit was simulated using ORCAD
capture and its output waveform was obtained.
VIVA QUESTIONS:
1. What is current time base generator? The circuit which produces current which linearly increases with time is called current
time base generator.
2. What are the application of the blocking oscillator? The blocking oscillator can be used as low impedance switch used to discharge a capacitor
very quickly. To produce large peak power pulses, both the types of oscillators cab be used.
The output of the blocking oscillator can be used to produce gating waveform with very low
mark space ratio. It may be used as frequency divider or counter in digital circuits.
3. List varies sweep circuits Exponential charging circuit
Constant-current charging circuit.
Miller circuit
poot strap circuit
Inductor circuit.
4. What do you mean by voltage time base generators? Circuits used to generate a linear variation of voltage with time are called voltage time
base generators.
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51
Exercise Number : 16
Title of the Exercise : MONOSTABLE MULTIVIBRATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of Monostable multivibrator by using ORCAD
capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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52
c) CIRCUIT DIAGRAM: MONOSTABLE MULTIVIBRATOR
d) MODEL GRAPH:
Output Vc2
Output Vc1
Output Vb1
Output Vb2
Time (s)
V
Vce(sat)
Vce(sat)
Vbe(sat)
Vbe(sat)
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e) RESULT: Thus the monostable multivibrator circuit was simulated using ORCAD capture and
its output waveform was obtained.
VIVA QUESTIONS:
1. Define resonance. The reactance of the capacitor equals that of the inductor reactance.
i.e C. = 1 / L.
2. What is Quality factor? The ratio of inductive reactance of the coil at resonance to its resistance is known
as quality factor.
Q = XL / R
3. Define gain bandwidth product of a tuned amplifier. The gain bandwidth(GBW) product is a figure of merit defined in terms of mid band
gain and upper 3-db frequency fh as GBW = | Aim fh | = gm / 2c
4. What is the other name for tuned amplifier? Tuned amplifiers used for amplifying narrow band of frequencies hence it is also
known as narrow band amplifier or Band pass amplifier.
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54
Exercise Number : 17
Title of the Exercise : BISTABLE MULTIVIBRATOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of bistable multivibrator by using ORCAD
capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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55
c) CIRCUIT DIAGRAM: BISTABLE MULTIVIBRATOR
d) MODEL GRAPH:
Output Vb1
V
Time (s)
Output Vb2 Vbe(sat)
Output Vc2
Vce(sat)
Vbe(sat)
Vce(sat)
Output Vc1
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e) RESULT: Thus the Bistable multivibrator circuit was simulated using ORCAD capture and its
output waveform was obtained.
VIVA QUESTIONS:
1. What is unilateralisation? It is the phenomenon by which a signal can be transmitted from the input to the output
alone and not viceversa. In an unilateralised amplifier both resistive and reactive effects are
cancelled.
2. What is stagger tuned amplifier? In this configuration one or more tuned amplifiers are cascaded each amplifier stage is
tuned to different frequencies. This results in decreased gain and increased bandwidth.
3. What is the effect of Q on stability? Higher the value of Q,provides better selectivity, but smaller bandwidth and larger
gain. Hence it provides less stability.
4. What is meant by unloaded and loaded Q of tank circuit.[ APR 2003 ] Unloaded Q is the ratio of stored energy to dissipated energy in a reactor or resonator.
The loaded Q (or) QL of a resonator is determined by how tightly the resonator is coupled to
its terminations.
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57
Exercise Number : 18
Title of the Exercise : CMOS INVERTER
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of cmos inverter by using ORCAD capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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Dr.NNCE ECE / IV SEM EC II & S LAB - LM
58
c) CIRCUIT DIAGRAM: CMOS INVERTER
e) RESULT:
Thus the CMOS Inverter circuit was simulated using ORCAD capture and its output
waveform was obtained.
0
0
V1 5v
M1
MbreakP
CLK DSTM1
M2
MbreakN
INPUT
OUTPUT
Analysis type:Time domain (transient)
Run to time=0.01ms
Maximum step size=0.2ms
Off time=0.5us On time=0.5us
1 1 1 1
1 1 1 1
0 0 0 0
0 0 0 0
Time(s)
V
Input
Output
d) MODEL
GRAPH
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VIVA QUESTIONS:
1. Mention the applications of class c tuned amplifier. One of the most common applications for mixer is in radio receivers. The mixer is
used to convert incoming signal to a lower frequency where it is easier to obtain the high gain
and selectivity required.
Mixer circuits are used to translate signal frequency to some lower frequency or to
some higher frequency. When it is used to translate signal to lower frequency it is called
down converter. When it is used to translate signal to higher frequency, it is called up
converter.
2. Mention the need for stagger-tuned amplifier. The double tuned amplifier gives greater 3 db bandwidth having steeper sides and flat
top. But alignment of double tuned amplifier is difficult. To overcome this problem two
single tuned amplifiers are cascaded.
3. What is principle of Hazel tine neutralization? Hazel tine introduced a circuit in which the troublesome effect of the collector to base
capacitance of the transistor was neutralized by introducing a signal which cancels the signal
coupled through the collector to base capacitance.
4. List the performance measure of a tuned amplifier. Selection of a desired radio frequency signal.
Effective quality factor.
Gain
Bandwidth.
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60
Exercise Number : 19
Title of the Exercise : CMOS NOR
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of CMOS NOR by using ORCAD capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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c) CIRCUIT DIAGRAM: CMOS NOR
d) MODEL GRAPH:
1 1 1 1
1 1 1 1 1
1 1 1
0 0 0 0 0 0
0 0 0 0 0
0 0 0 0 0 0 0
Input A
Input B
Output
Time(s)
V
0
0
0
V1 5V
M4
MbreakN
M2
MbreakP
M1
MbreakP
CLK DSTM1
CLK DSTM2
M3
MbreakN
Input A
Input B Output
Off time=1us On time=1us
Off time=0.5us On time=0.5us
Analysis type:Time domain (transient)
Run to time=0.01ms
Maximum step size=0.2us
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e) RESULT: Thus the CMOS NOR circuit was simulated using ORCAD capture and its output
waveform was obtained.
VIVA QUESTIONS:
1. What are the characteristics of an ideal tuned amplifier? Selects a single radio frequency and amplifiers the same by rejecting all other
frequencies.
Bandwidth is zero.
Harmonic distortion is zero.
2. Write down the relationship between bandwidth and effective Q of a tuned amplifier? Bandwidth = o / Q effective.
3. What are the different methods of coupling? (or) Point out different methods of coupling the load to a tuned amplifier.
The different methods of coupling the load to a tuned amplifier are:
Capacitive coupling.
Inductive coupling.
4. Why tuned amplifier cannot be used at low frequency? For low frequencies the size L and C are large. So the circuit will be bulky and
expensive, hence the tuned amplifiers cannot be used at low frequency.
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Exercise Number : 20
Title of the Exercise : CMOS NAND
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of CMOS NAND by using ORCAD capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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c) CIRCUIT DIAGRAM: CMOS NAND
d) MODEL GRAPH:
Input B
V
Output 0 0
Input A
1
1
1 0
1
0
0
0
0
0 0
0
0 0
0 0
0
0
1
1 1
1
0
1
Time(s)
1
1
0 0
0
0
M4
MbreakP
M5
MbreakP
M6
MbreakN
M7
MbreakN
V2
5V
CLK DSTM3
CLK DSTM4
Input A
Input B
Output
Off time=1us On time=1us
Analysis type:Time domain (transient)
Run to time=0.01ms
Maximum step size=0.2us
Off time=0.5us On time=0.5us
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e) RESULT: Thus the CMOS NAND circuit was simulated using ORCAD capture and its output
waveform was obtained.
VIVA QUESTIONS:
1. What is the need for differential amplifiers? Differential amplidiers are small signal direct coupled amplifiers used to amplify the
difference between two signals. The need for differential amplifier arises in physical
measurements, instrumentation amplifiers and medical instrumentation.
2. What are the advantages of Differential Amplifiers? * High voltage gain.
* High input impedence
* High Bandwidth
* Good bias stability.
3. Define CMRR. Common Mode Rejection Ratio(CMRR) is the ability of the differential amplifiers to
reject the common mode signals. It is defined as the ratio of difference mode gain Ad to
common mode gain Ac.
4. Why Differential amplifiers are widely used in Integrated Circuits? It has good bias stability and good voltage gain without the use of large bypass
capacitors. Hence it is used in ICs.
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Exercise Number : 21
Title of the Exercise : DIGITAL TO ANALOG CONVERTER
Date of the Exercise :
OBJECTIVE (AIM) OF THE EXPERIMENT
To simulate and obtain the output waveform of digital to analog converter by using ORCAD
capture.
FACILITIES REQUIRED AND PROCEDURE a) FACILITIES REQUIRED TO DO THE EXPERIMENT:
ORCAD capture
b) PROCEDURE:
1. Start the program 2. Select the ORCAD release 9 capture CIS 3. Go to new and select project 4. Create the title of the project 5. Drag the elements as per the circuit diagram requirement. 6. Make connections as per the circuit diagram using wire icon. 7. Create the new simulation 8. Set the output level setting. 9. Placed the voltage markers in input and output mode. 10. Run the circuit diagram and print the output.
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c) CIRCUIT DIAGRAM:
d) MODEL GRAPH:
Time(s)
Input B0
Input B1
Input B2
Input B3
Output
V
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0
0 0
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1
1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1
1
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RESULT:
Thus the digital to analog converter circuit was simulated using ORCAD capture and
its output waveform was obtained.
VIVA QUESTIONS:
1. What are the basic elements of power supply ? (i) Transformer
(ii) Rectifier.
(iii) Filter.
2. What is ripple factor()? Ripple factor () may be defined as the ratio of the root mean square (rms) value of the ripple voltage to the absolute value of the dc component of the output voltage, usually expressed as
a percentage. However, ripple voltage is also commonly expressed as the peak-to-peak value.
This is largely because peak-to-peak is both easier to measure on an oscilloscope and is
simpler to calculate theoretically. Filter circuits intended for the reduction of ripple are
usually called smoothing circuits.
3. What is a rectifier? A rectifier is an electrical device that converts alternating current (AC), which periodically
reverses direction, to direct current (DC), which flows in only one direction. The process is
known as rectification.
4. Define SMPS . A switched-mode power supply (switching-mode power supply, SMPS, or simply switcher)
is an electronic power supply that incorporates a switching regulator in order to be highly
efficient in the conversion of electrical power.
An SMPS is usually employed to efficiently provide a regulated output voltage, typically at a
level different from the input voltage.
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Exercise/Experiment Number: 22
Title of the exercise/experiment : Inverting, Non-inverting and Differential amplifiers
Date of the experiment :
AIM: To construct and test the performance of an Inverting, Non-inverting amplifier
and Differential amplifier using IC A 741
APPARATUS REQUIRED:
DESIGN
:
INVERTING AMPLIFIER:
Let A = -5; R1 = 1K A = Rf / R1 Rf = 5 K Rcomp = R1 Rf / R1 + Rf
= 833
NON-INVERTING AMPLIFIER:
Let A = 6; R1 = 1K A = 1 + (Rf / R1)
Rf = 5 K Rcomp = R1 Rf / R1 + Rf
= 833 NON-INVERTING AMPLIFIER:
Let A = 100; R1 = 1K A = R2 / R1
R2 = 100 K
S. No. Name Range Quantity
1 Dual Power Supply (0-30)V 1
2 Resistors 1K;5 K;100 K Each 2
3 Regulated Power Supply (0-30)V 1
4 IC A 741 - 1
5 Voltmeter (0-50)V 1
6 Connecting Wires - -
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CIRCUIT DIAGRAM:
NON-INVERTING AMPLIFIER: MODEL GRAPH:
DIFFERENTIAL AMPLIFIER:
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THEORY:
INVERTING AMPLIFIER:
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.
DIFFERENTIAL AMPLIFIER:
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:
INVERTING AMPLIFIER:
S.No Input Voltage (in volts) Output Voltage (in volts)
1
1
9.93
NON- INVERTING AMPLIFIER:
S.No Input Voltage (in volts) Output Voltage (in volts)
1
1
11.2
DIFFERENTIAL AMPLIFIER:
S.No Input Voltage (in volts) Output Voltage (in volts)
1
2
V1 V2
9.74
9.80
3 2
2 3
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.
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Readings are tabulated and gain was calculated and composed with designed values. RESULT Thus the Inverting, Non-inverting and Differential amplifier using op-amp was designed and tested.
VIVA 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.
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Exercise/Experiment Number: 23
Title of the exercise/experiment : DIFFERENTIAL AMPLIFIER USINGBJT
Date of the experiment :
AIM:
To construct a differential amplifier using BJT and to determine the dc collector current of
individual transistors and also to calculate the CMRR.
APPARATUS REQUIRED:
S.No. Name Range Quantity
1. Transistor BC107 2
2. Resistor 4.7k, 10k 2,1
3. Regulated power supply (0-30)V 1
4. Function Generator (0-3) MHz 2
5. CRO 30 MHz 1
6. Bread Board 1
OBSERVATION
VIN = V1 V2 V0 =
Ad = V0/ VIN
For the differential mode operation the input is taken from two different sources and the
common mode operation the applied signals are taken from the same source
Common Mode Rejection Ratio (CMRR) is an important parameter of the differential
amplifier. CMRR is defined as the ratio of the differential mode gain, Ad to the common
mode gain, Ac.
CMRR = Ad / Ac
In ideal cases, the value of CMRR is very high.
OBSERVATION
VIN =VO =AC = VO / VIN FORMULA:
Common mode Gain (Ac) = VO / VIN
Differential mode Gain (Ad) = V0 / VIN
Where VIN = V1 V2
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CIRCUIT DIAGRAM
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Dr.NNCE ECE / IV SEM EC II & S LAB - LM
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Common Mode Rejection Ratio (CMRR) = Ad/Ac
Where, Ad is the differential mode gain
Ac is the common mode gain.
THEORY:
The differential amplifier is a basic stage of an integrated operational amplifier.
It is used to amplify the difference between 2 signals.
It has excellent stability, high versatility and immunity to noise
. In a practical differential amplifier, the the common mode signal.
Transistor Q1 and Q2 have matched characteristics. The values of RC1 and RC2 are
equal. Re1 and Re2 are also equal and this differential amplifier is called emitter coupled
differential amplifier. The output is taken between the two output terminals
PROCEDURE:
1. Connections are given as per the circuit diagram.
2. To determine the common mode gain, we set input signal with voltage Vin=2V
and determine Vo at the collector terminals. Calculate common mode gain, Ac=Vo/Vin. 3. To determine the differential mode gain, we set input signals with voltages V1 and
V2. Compute Vin=V1-V2 and find Vo at the collector terminals. Calculate differential mode
gain, Ad=Vo/Vin.
4. Calculate the CMRR=Ad/Ac. 5. Measure the dc collector current for the individual transistors.
RESULT:
Thus, the Differential amplifier was constructed and dc collector current for the
individual transistors is determined. The CMRR is calculated as
Viva questions 1.What is an amplifier?
An amplifier is a device which produces a large electrical output of similarcharacteristics to
that of the input parameters.
2.. How are amplifiers classified according to the input?
1. Small signal amplifier 2. Large signal amplifier
3.How are amplifiers classified according to the transistor configuration?
Common emitter amplifier 2. Common base amplifier 3. Common collector
amplifier
4. What is the different analysis available to analyze a transistor?
1. AC analysis 2. DC analysis
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Exercise/Experiment Number: 24
Title of the exercise/experiment :CLASS B COMPLEMENTARY SYMMETRY
POWER AMPLIFIER
Date of the experiment :
AIM:
To construct a Class B complementary symmetry power amplifier and observe the
waveforms with and without cross-over distortion and to compute maximum output power
and efficiency.
APPARATUS REQUIRED:
S.No. Name Range Quantity
1. Transistor CL100, BC558 1,1
2. Resistor 4.7k,15k 2,1
3. Capacitor 100F 2
4. Diode IN4007 2
5. Signal Generator (0-3)MHz 1
6. CRO 30MHz 1
7. Regulated power supply (0-30)V 1
8. Bread Board 1
FORMULA:
Input power, Pin=2VccIm/ Output power, Pout=VmIm/2
Power Gain or efficiency, =/4(Vm/Vcc) 100 . THEORY: A power amplifier is said to be Class B amplifier if the Q-point and the input signal
are selected such that the output signal is obtained only for one half cycle for a full input
cycle. The Q-point is selected on the X-axis. Hence, the transistor remains in the active
region only for the positive half of the input signal.
There are two types of Class B power amplifiers: Push Pull amplifier and complementary
symmetry amplifier. In the complementary symmetry amplifier, one n-p-n and another p-n-p
transistor is used. The matched pair of transistor are used in the common collector
configuration. In the positive half cycle of the input signal, the n-p-n transistor is driven into
active region and starts conducting and in negative half cycle, the p-n-p transistor is driven
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into conduction. However there is a period between the crossing of the half cycles of the
input signals, for which none of the transistor is active and output, is zero.
MODEL GRAPH
f 1 f2 f (Hz)
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TABULATION:
FREQUENCY RESPONSE OF CASCODE AMPLIFIER
Keep the input voltage constant (Vin) =
Frequency (in Hz) Output Voltage (in volts) Gain = 20 log (Vo / Vin) (in dB)
RESULT:
Thus, the Class B amplifier was constructed and the gain was determined.
VIVA QUESTION:
1. What is feed back?
It is the process of injecting some energy from the output and then returns it back
tothe input.
2. What is the disadvantage of negative feed back? Reduces amplifier gain.
3. Define sensitivity. It is the ratio of percentage change in voltage gain with feedback to the percentage
change in voltage gain without feed back.
4. Define Desensitivity.
It is the ratio of percentage change in voltage gain without feedback to thepercentage
change in voltage
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Exercise/Experiment Number: 25
Title of the exercise/experiment :CASCADE AMPLIFIER
Date of the experiment :
AIM:
To construct a cascode amplifier circuit and to plot the frequency response
characteristics.
APPARATUS REQUIRED:
S.No. Name Range Quantity
1. Transistor BC107 2
2. Resistor
22k,6 k,700 ,470 16 k,6.2 k,3.3 k 1.1 k
1,1,1,1,
1,1,1,
1
3. Regulated power supply (0-30)V 1
4. Signal Generator (0-3)MHz 1
5. CRO 30 MHz 1
6. Bread Board 1
7. Capacitor 0.01F 3
THEORY:
A cascode amplifier consists of a common emitter amplifier stage in series with a common
base amplifier stage. It it one approach to solve the low impedance problem of a common
base circuit. Transistor Q1 and its associated components operate as a common emitter
amplifier, while the circuit of Q2 functions as a common base output stage. The cascade
amplifier gives the high input impedance of a common emitter amplifier, as well as the good
voltage gain and frequency performance of a common base circuit.
PROCEDURE:
1. Connections are made as per the circuit diagram.
2. The waveforms at the input and output are observed for cascade operations varying the
input frequency.
3. The biasing resistances needed to locate the Q-point are determined.
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4. Set the input voltage as 1V and by varying the frequency, note the output voltage.
5. Calculate gain=20 log (Vo / Vin.)
6. A graph is plotted between frequency and gain.
CIRCUIT DIAGRAM:
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TABULATION:
Keep the input voltage constant, Vin =
Frequency (in Hz) Output Voltage (in volts) Gain= 20 log(Vo/Vin) (in dB)
RESULT:
Thus, the Cascade amplifier was constructed and the gain was determined.
VIVA QUESTIONS:
1.What is biasing?
To use the transistor in any application it is necessary to provide sufficient voltage
and current to operate the transistor. This is called biasing. 2. What is the necessary of the coupling capacitor?
It is used to block the c signal to the transistor amplifier. It allows a c &blocks the d c.
3. What is reverse saturation current?
The current due to the minority carriers is called the reverse saturation current.
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LIST OF QUESTION SET
1. a) Design a differential amplifier circuit and calculate its CMRR.
b) Design and simulate a Monostable Multivibrator with frequency 2 KHz
using ORCAD.
2. a) Design a Wein bridge oscillator with frequency of oscillation 1 KHz.
b) Simulate a CMOS NAND using ORCAD.
3. a) Design a Colpitts oscillator with frequency of oscillation 12 KHz.
Specifications:
VCC=12V, S=6, ICQ=1.7mA, VRE=3V.
b) Simulate a CMOS Inverter using ORCAD.
4. a) Design a RC Phase shift oscillator with frequency of oscillation 1 KHz.
b) Design and simulate a Symmetrical Astable Multivibrator with frequency
2 KHz using ORCAD.
5. a) Design a differential amplifier circuit and calculate its CMRR.
b) Design and simulate a Asymmetrical Astable Multivibrator with frequency
2 KHz using ORCAD.
6. a) Design a single tuned Class C amplifier with resonant frequency 9KHz.
Specifications:
QL=1, RL= 1K, L= 1mH. b) Design and simulate a second order Butterworth low pass filter with
frequency 1 KHz using ORCAD.
7. a) Design a Class B amplifier with resonant frequency 9KHz.
b) Simulate a differentiator with sine wave input using ORCAD.
8. a) Design a Hartley oscillator with frequency of oscillation 12 KHz.
Specifications:
VCC=12V, S=6, ICQ=1.7mA, VRE=3V.
b) Simulate a CMOS NOR using ORCAD.
9. a) Design a Colpitts oscillator with frequency of oscillation 12 KHz.
Specifications:
VCC=12V, S=6, ICQ=1.7mA, VRE=3V.
b) Design and simulate a Bistable Multivibrator with frequency 2 KHz using
ORCAD.
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10. a) Design a Wein bridge oscillator with frequency of oscillation 1 KHz.
b) Simulate a differenti