LABORATORY MANUAL

ANALOG ELECTRONICS

B.TECH

3RD SEMESTER

DEPARTMENT OF ELECTRICAL ENGINEERING

JHARKHAND RAI UNIVERSITY KAMRE, RANCHI

JHARKHAND

EXPERIMENT NO:-01

AIM: To observe the characteristic of LED.

APPRATUS REQUIRED:

1) LED Kit 2) Multimeter 3) Connecting wire 4) Voltmeter (0-10v) 5) DC power supply 6) Rheostat

THEORY: When an electron comes down its higher energy level to lower

energy level, its limit energy in form of a photon. The energy of this

photon is equal to the energy gap between this to energy levels. When an

PN junction diodes is forward bias , current lows through the diode. Flows

of current through the semiconductor is caused by flow of free electron in

opposite direction of current and flow of holes in the direction of current,

Hence during flows of this charges carriers, there will be recombination .

OBSERVATION TABLE :-

For R=1.5kΩ

Colour Vin I out

White

Green

Red

For R=1 kΩ

Colour Vin I out White

Green

Red

GRAPH:-

PRECAUTIONS:

1) Reading should be taken carefully. 2) Instruments should be errorless.

RESULT: Hence, We observed the characteristic of LED.

EXPERIMENT NO: 02

AIM: To observe the output waveforms of inverting and non-inverting amplifiers.

APPARATUS REQUIRED:

1. Op-amp-741(inverting and non-inverting operational amplifier) 2. CRO(cathode ray oscilloscope) 3. Connecting wire

THEORY: INVERTING AMPLIFIER

This is the most widely used of all the op-amp circuits. The output V0

is feedback to the inverting input through the Rf-Rin network as shown in

figure where Rf is the feedback resistor. The input signal Vi is applied to the

inverting input terminal through Rin and non-inverting input terminal of

op-amp is grounded.

The output Vo is given by –

Vo=Vi(-Rf/Rin)

Where the gain of amplifier is –Rf/Rin

The negetive sign indicates a phase shift of 1800 between Vi and Vo. The

effective input impedences is Ri. An inverting amplifier uses negative.

NON-INVERTING AMPLIFIER

The Circuit diagram of non-inverting terminal is shown in the figure below.

Here, the signal is applied to non-inverting input terminal and feedback is

given to the inverting terminal. The circuit amplifier the input signal

without inverting it the output voltage is given by

Vout = Vin(1+R2/R1)

The voltage is given iby-

Av=Vout/Vin =(1+R2/R1)

Fig:- diagram of non-inverting amplifiear

Wave form of inverting or non –inverting amplifier

PERCAUTION:

1) All the connection should be neat and tight. 2) The supply current should be proper.

RESULT: Hence, We observed the wave form of inverting and non-inverting amplifier.

EXPERIMNT NO: 03

AIM: To observe the output wave form of summing and difference amplifier.

APPRATUS REQUITRED:

1) Op-amp-741 kit 2) CRO 3) Connecting wire

THEORY:

SUMMER:- The summing circuit using op-amp as inverting mode

configuration with three input Va, Vb, Vc is shown in figure. The circuit act

as summing amplifier that means at the O/p, We get the addition of the

three input according to the circuit given in the figure O/p equation is as:

Va=Vb=Ov

I1 = (V1 – Va)/R1 = V1/R1

I2=(V2- Va)/R2 = V2/R2

I=(Va – Vo)/Rf = -Vo/Rf

Using KCL-

I= I1+I2

=-Vo/Rf = (V1/R1) + (V2/R2) If R1=R2

=-V0/Rf = (V1+V2)/R1

Vo = (-Rf/R1)V1+V2

DIFFERENT AMPLIFIER:

Different circuit using op-amp is shown in the figure. This circuits act as a

difference means when the input to Va and Vb is given at two terminal

as shown in the circuit then the output terminal is the difference of the

two input. Theoritical equation is given as –

Vo = (Rf /R1)V2-V1

*Diagram of differential amplifier

I/O waveform of summer amplifier

I/O waveform of differential amplifier

PRECAUTION:

1) Make sure that connections are neat and tight. 2) The supply current should be proper. 3) Instrument should be errorless.

RESULT: Hence, we observed the input and output waveform of summing and difference amplifiers.

EXPERIMENT NO: 04

AIM: To Study the switching action of FET.

APPARATUS REQUIRED:

1) Switching action of FET Trainer. 2) Connecting wire.

THEORY:

FET:- It stands for field effect transistor. It is a transistor that uses and

electric field to control the shape and hence the electric conductivity of a

channel of one tab change carrier in semiconductor material FET are also

known as unipolar transistor and as they involved signal carrier tap

operation. The FETs three terminal are sources, drain and gate. There

are two types of Transistor-

1) JFET:- It stand for Junction field Effect Transistor.

JFET is a one of the simplest transistor from the structural point of

view. It is a voltage control semiconductor device, in this the current

is carried by only one type of carriers. So , It is a unipolar device, It

isa very high input electrical resistance. 2) MOSFET:-

It stands for metal oxide semiconductor field effect transistor. It is a

capable off voltage gain signal proper gain. The MOSFET is the one of

Integrated circuit design as thousands of those can be fabricated in a

signal chip because of it very small size.

It is a four terminal devices. The drain and source terminal are

connected to the heavily doped regions. The gate terminal is

connected top on the oxide layer and the substrate on body

terminal is connected to the intrinsic semiconductor.

OBSERVATION TABLE:

When switch is off_

S.No Voltage I(Ammeter)

When Switch is on_

S.No Voltage I(Ammeter)

PRECAUTION:

1) When performing the experiment do not exceed the rating of the FET. This lead to damage FET.

2) Connect Voltmeter and ammeter with current polarities as shown

in the circuit diagram.

3) Do not Switch on the power supply unless the circuits connection are checked as per the circuit diagram

4) Properly identifies the sources, drain and gate terminal of

the transistor.

RESULT: Hence the switching action of FET is studied.

EXPERIMENT NO :05

AIM: To Study the switching action of BJT.

APPARATUS REQUIRED:-

1) Switching action of BJT trainer. 2) Connecting Wire.

THEORY:-

BJT:- It stands for Bipolar Junction Transistor .a Bipolar junction has three

terminals connected to three doped semiconductor .In an NPN transistor ,

a thin and lightly doped P-type been is sandwiched between a heavily

doped N-type emitter and another N-type collector ; while in a PNP

transistor , a thin and lightly doped N-type base is sandwiched between a

heavily doped P-type emitter and another P – type collector

TRANSISTOR:-

Transistor was invented “ By the Bell-Lab at USA in 1947”. It is current

controlling device after the invention of it replaced vacuum triode which

was voltage control device due to its compact size .it is three terminal

device i.e Emitter ,Base and collector.

Emitter:-In the symbol of transistor the segment with arrow denotes the

emitter part of the transistor .Its main function is to supply majority charge

carrier (electron in case of N-P-N transistor and holes in case of P-N-P

transistor) to the base. It is always forward biased with respect to base so

that is able to supply majority charge carrier to the base.

Base:-It is middle section of the transistor and it is very thin as

comparison to either emitter or collector .So that it may pass most of the

injected charge carrier to the collector.

Collector :- The remaining section of the transistor is the collector .Its main

Function is to collect majority charge carrier .Collector is always reversed

biased .So as to remove the charge carrier away from its junction with the

base .It is moderately doped.

OBERVATION TABLE:-

When switch is off mode

When switch is on mode

S.No Voltage(volt) Current(ampere)

1

2

3

4

S.No Voltage(volt) Current (ampere)

PRECAUTION:-

1) When performing the experiment do not exceed the rating of the BJT. This lead to damage BJT.

2) Connect Voltmeter and ammeter with current polarities as shown in

the circuit diagram.

3) Do not Switch on the power supply unless the circuits connection are checked as per the circuit diagram.

4) Properly identifies the Emitter, Base and Collector terminal of the transistor.

RESULT: - Hence, the switching action of BJT has been studied.

EXPERIMENT: - 06

AIM: - To study the output waveform of Filter.

APPARATUS REQUIRED:- 1) MATLAB Software

2)Computer

THEORY: - An electric field is a network is design to attenuate certain

frequency but pass others without attenuation. A filter circuit possess at

least one band. A band of frequency in which the output is approximately

equal to the output and attenuation band in which output is zero.

There are three types of filter:-

1) Analog or digital Filter: - An analog filter uses analog electronic

circuits made up from components such as resistors, capacitors and

op-amps to produce the required filtering effect. Such filter circuits

are widely used in such applications as noise reduction, video signal

enhancement, graphic equalizers in hi-fi systems, and many other

areas. A digital filter uses a digital processor to perform numerical

calculations on sampled values of the signal. The processor may be

a general-purpose computer such as a PC, or a specialized DSP

(Digital Signal Processor) chip.

2) Passive or Active filter:- Passive implementations of linear filters are based on combinations of resistors (R), inductors (L) and capacitors

(C). these types are collectively known as passive filters, because

they do not depend upon an external power supply and/or they do

not contain active components such as transistors.

An active filter is a type of analog electronic filter that uses active

components such as an amplifier. Amplifiers included in a filter

design can be used to improve the performance and predictability of

a filter, while avoiding the need for inductors (which are typically

expensive compared to other components).

3) Audio frequency or Radio frequency filter:- An RF Filter, or radio

frequency filter, is an electronic filter which is designed to operate

on signals in medium to extremely high frequencies. These ranges

are used in radio, television and wireless communications. Therefore

most RF devices include some kind of filtering on the signals

transmitted or received.

DIAGRAM:

WAVEFORM:-

PRECAUTION: -

1) Make sure that connections are neat and tight. 2) The supply current should be proper. 3) Instrument should be errorless.

RESULT:- Hence, the output waveform of filter has been studied.

EXPERIMENT: 06

AIM: - To Study the characteristics of MOSFET in different modes.

APPARATUS REQUIRED:

1) MOSFET characteristics Apparatus

2) Connecting Wires

THEORY:-

MOSFET: MOSFET (metal-oxide semiconductor field-effect transistor,

pronounced MAWS-feht ) is a special type of field-effect transistor ( FET

) that works by electronically varying the width of a channel along which

charge carriers ( electron s or hole s) flow. The wider the channel, the

better the device conducts.

Although the MOSFET is a four-terminal device with source (S), gate (G),

drain (D), and body (B) terminals, the body (or substrate) of the MOSFET is

often connected to the source terminal, making it a three-terminal device

like other field-effect transistors. Because these two terminals are normally

connected to each other (short-circuited) internally, only three terminals

appear in electrical diagrams.

CIRCUIT DIAGRAM:-

OBSERVATION TABLE:-

VGS=1V

S NO. VDS ID

VGS=2V

S NO. VDS ID

VGS=3V

S NO. VDS ID

VGS=4V

S NO. VDS ID

GRAPH:-

PRECAUTION:

1) Make sure that connections are neat and tight. 2) The supply current should be proper. 3) Instrument should be errorless.

RESULT: Hence the characteristics of MOSFET in different modes has been Studied.

EXPERIMENT NO:-08

CHARACTERISTICS OF PN JUNCTION DIODE

AIM: To study the PN junction diode characteristics under Forward & Reverse bias conditions.

APPARATUS REQUIRED-

1. PN Junction Kit

2. Ammeter,

3. Voltmeter,

4. Connecting wires,

5. Resistor

THEORY: A PN junction diode is a two terminal junction device. It conducts only in one direction (only on forward biasing). FORWARD BIAS:

On forward biasing, initially no current flows due to barrier potential. As the applied

potential exceeds the barrier potential the charge carriers gain sufficient energy to

cross the potential barrier and hence enter the other region. The holes, which are

majority carriers in the P-region, become minority carriers on entering the N-regions,

and electrons, which are the majority carriers in the N-region, become minority

carriers on entering the P-region. This injection of Minority carriers results in the

current flow, opposite to the direction of electron movement.

REVERSE BIAS:

On reverse biasing, the majority charge carriers are attracted towards the

terminals due to the applied potential resulting in the widening of the depletion

region. Since the charge carriers are pushed towards the terminals no current

flows in the device due to majority charge carriers. There will be some current in

the device due to the thermally generated minority carriers. The generation of

such carriers is independent of the applied potential and hence the current is

constant for all increasing reverse potential. This current is referred to as

Reverse Saturation Current (IO) and it increases with temperature. When the

applied reverse voltage is increased beyond the certain limit, it results in

breakdown. During breakdown, the diode current increases tremendously.

PROCEDURE:

FORWARD BIAS:

1. Connect the circuit as per the diagram.

2. Vary the applied voltage V in steps of 0.1V.

3. Note down the corresponding Ammeter readings If.

4. Plot a graph between Vf & If

OBSERVATIONS

1. Find the d.c (static) resistance = Vf / If.=

2. Find the a.c (dynamic) resistance r = δV / δI (r = V/ I) =

V2 −

V1 .=

I

2 − I1 3. Find the forward voltage drop = [Hint: it is equal to 0.7 for Si and 0.3

for Ge]=

REVERSE BIAS:

1. Connect the circuit as per the diagram.

2. Vary the applied voltage Vr in steps of 0.5V.

3. Note down the corresponding Ammeter readings Ir.

4. Plot a graph between Vr & Ir

5. Find the dynamic resistance r = δV / δI.

FORMULA FOR REVERSE SATURATION CURRENT (IO):

Io = ∂I/[exp(∂V/ηVT)]-1=

Where VT is the voltage equivalent of Temperature = kT/q

k is Boltzmann’s constant, q is the charge of the electron and T is

the temperature in degrees Kelvin.

η =1 for Silicon and 2 for Germanium

CIRCUIT DIAGRAM:

FORWARD BIAS:

REVERSEBIAS MODEL GRAPH:-

TABULAR FORM:-

S.No. Voltage(Vf)(in V) Current(If)( µA) S.No. Voltage(Vr)(in V) Current(If)( µA)

RESULT: Thus, the V-I characteristics of P-N junction is verifi