Scribd
Upload
122 views6 pages

Engineering Lab: Instrumentation Amplifier

This document describes Lab Experiment #4 on instrumentation amplifiers. The objectives are to design an instrumentation amplifier with a specified gain and investigate its performance characteristics. The lab will use a breadboard, power supply, multimeter, resistors, op-amp IC and function generator. An instrumentation amplifier is a differential amplifier that buffers the input stages for easy impedance matching. It has features like low offset voltage, high CMRR and input resistance. The lab will construct the circuit, calculate output voltages at different gain settings, measure the actual outputs and compare the calculated vs measured values in a table. Questions at the end ask to simulate the circuit in software and discuss differences between instrumentation and difference amplifiers and applications of instrumentation amplifiers.

Uploaded by

Talha Jamal
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
122 views6 pages

Engineering Lab: Instrumentation Amplifier

This document describes Lab Experiment #4 on instrumentation amplifiers. The objectives are to design an instrumentation amplifier with a specified gain and investigate its performance characteristics. The lab will use a breadboard, power supply, multimeter, resistors, op-amp IC and function generator. An instrumentation amplifier is a differential amplifier that buffers the input stages for easy impedance matching. It has features like low offset voltage, high CMRR and input resistance. The lab will construct the circuit, calculate output voltages at different gain settings, measure the actual outputs and compare the calculated vs measured values in a table. Questions at the end ask to simulate the circuit in software and discuss differences between instrumentation and difference amplifiers and applications of instrumentation amplifiers.

Uploaded by

Talha Jamal
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 6

LAB NO # 4

BAHRIA UNIVERSITY KARACHI CAMPUS


Department of Electrical Engineering

INSTRUMENTATION & MEASUREMENTS

LAB EXPERIMENT # 4

Instrumentation Amplifier
OBJECTIVE:

a) To design an Instrumentation Amplifier with specified gain requirements.


b) To verify and investigate performance characteristics of Instrumentation Amplifier.

EQUIPMENT: -
1. Breadboard
2. Dual Power Supply
3. Digital Multi Meter (DMM)
4. Few Resistors and connecting wires
5. LM324 Quad Op-amp IC
6. Function generator

THEORY: -
Instrumentation amplifier is a kind of differential amplifier with additional input buffer stages. The
addition of input buffer stages makes it easy to match (impedance matching) the amplifier with the
preceding stage. Instrumentation are commonly used in industrial test and measurement application.
The instrumentation amplifier also has some useful features like low offset voltage, high CMRR
(Common mode rejection ratio), high input resistance, high gain etc.
An instrumentation amplifier is a circuit that provides an output used on the difference between two
inputs (times a scale factor). Out of three op-amps first two act as noninverting amplifiers whereas
the third one works as a difference amplifier. The output voltage can be shown in equation 4.1.

Eq.4.1

The circuit can be manufactured using a single quad op-amp IC or, separate op-amps can be used with
precision resistors.
LAB NO # 4

Figure 4.1: Instrumentation Amplifier

Pin Configuration Diagram :

Figure 4.2: Pin Configuration


LAB NO # 4

Table 4.1: Pin Functions

QUAD Op-Amp IC (LM324):

LM324 is a 14pin IC consisting of four independent operational amplifiers (op-amps) compensated in


a single package. Op-amps are high gain electronic voltage amplifier with differential input and,
usually, a single-ended output. The output voltage is many times higher than the voltage difference
between input terminals of an op-amp.

These op-amps are operated by a single power supply LM324 and need for a dual supply is
eliminated. They can be used as amplifiers, comparators, oscillators, rectifiers etc. The conventional
op-amp applications can be more easily implemented with LM324. Pin configuration of LM324 is
shown in figure 4.1 and explanation of those pin in TABLE 4.1.
LAB NO # 4

TABLE 4.2: INSTRUMENTATION AMPLIFIER


Serial No. Gain Control Resistor (KΩs) Output Voltage (V)

Calculated Measured
1 2K
2 3K
3 4K
4 5K
5 6K
6 7K
7 8K
8 10K

Circuit Diagram: -

Figure 4.3: Instrumentation Amplifier

PROCEDURE AND OBSERVATION: -


1. Construct the circuit as shown in figure 4.2.
2. Calculate the output voltage using equation (4.1).
3. Using DMM measure the output voltage and write in TABLE 4.2.
LAB NO # 4

CALCULATIONS:
LAB NO # 4

EXERCISE:
Q1: Simulate instrumentation amplifier using MULTISIM software and attach the obtained output
results.

Q2: What is the difference between a Difference Amplifier, and an Instrumentation Amplifier?

Q3: Write some key applications of an Instrumentation Amplifier.

CONCLUSION:

You might also like