Download Experiment 4 - Electrical and Computer Engineering

ADDIS ABABA UNIVERSITY
INSTITUTION OF TECHNOLOGY
DEPARTMENT OF ELECTRICAL & COMPUTER ENGINEERING
LABORATORY REPORT
Course number: Eceg: - 2206
Experiment Number: 04
Title:
Operational Amplifier
By: _
Group No. :
Date of Experiment. 08/22-04-2012
Date of Submission. 28-04-2012
USED EQUIPMENT & COMPONENTS
No
Description
1
Operational amplifier board
2
2 Variable DC Power source
3
Electronic or Voltmeter
4
Cathode Ray Oscilloscope
5
Function Generator
6
Conducting Wires
7
Decade Resistor
8
Transistor, 2.2k, 120, 82K, 100K,33K, 1k & 1.0K
9
Circuit Board
DIFFERENCIAL AMPLIFIER
An operational amplifier, or op-amp, is a very high gain differential amplifier with high input impedance and
low output impedance. Typical uses of the operational amplifier are to provide voltage amplitude changes
(amplitude and polarity), oscillators, filter circuits, and many types of instrumentation circuits. An op-amp
contains a number of differential amplifier stages to achieve a very high voltage gain. A basic op-amp with
two inputs and one output as would result using a differential amplifier input stage. The operational amplifier
is an extremely efficient and versatile device. Its applications span the broad electronic industry filling
requirements for signal conditioning, special transfer functions, analog instrumentation, analog computation,
and special systems design. The analog assets of simplicity and precision characterize circuits utilizing
operational amplifiers.
Figure 1, Basic op-amp.,
Op Amp Package
Single-ended input operation results when the input signal is connected to one input with the other input
connected to ground.
Figure 2, Single-ended operation.
CALCULATIONS
Gain(A) = Vo / Vi
= -Rf /R2
Vo= Vi 1 + Vi 2
Vo = (-R1/R2)Vi 1 + (-R1/R3)Vi 2
Vo=f(Vin)
PROCEDURE
Inverting amplifier
1. setup the circuit according to circuit figure 3, and VCC set to 12V and plot the transfer characteristic voltage
Vo = f (Vin) -12 <= Vin <= 12V
a) R2 = 50KΩ
R1 = 100kΩ
b) R2 = 50KΩ
R1 = 50kΩ
c) R2 = 100KΩ
R1 = 50kΩ
2. The signal generator connects at the input terminal generating a 100Hz, 16Vpp. And Connect to the oscilloscope
and sketch.
R1
12v
R2
Vi
+
Vo
-12v
Figure 3. Inverting Amplifier
Summation
3. setup the circuit according to circuit figure 4
a) Vi1 = -1.5v, Vi2 = -2.8v
A=1
b) Vi1 = -4.5v, Vi2 = +3.5v
A=2
4. Measure the output voltage Vo
R1
R2
12v
Vi 1
R3
+
Vi 2
Vo
-12v
Figure 4. Inverting Summing Amplifier
Non-Inverting Amplifier
5. Setup the circuit according to circuit figure 5 and plot the transfer characteristic voltage
Vo = f (Vin) -12 <= Vin <= 12V
take R1 = R2 = 50kΩ
6. Apply a sinusoidal input signal input signsl of 100Hz and 16Vpp and observe the output voltage.
R1
12v
R2
Vi
+
-
R1
-12v
R2
Figure 5. Non-Inverting Amplifier
Vo
Integrator
7. Setup the circuit according to circuit figure 6 with R1 = 100k, R2 = 500Ω C=10nF
8. Apply a sinusoidal input signal input signsl of 50kHz and 10Vpp and observe the output voltage Vo & Vin.
9. Apply a square wave from 5kHz and 1Vpp and observe the output voltage Vo and Vin.
10. Vary the square wave from 500Hz to 50kHz and 10Vpp and observe the output voltage Vo
C1
12v
R1
+
Vi
Vo
-12v
Figure 5. OP-Amp Integrator
RESULTS
1, A,
Vin
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
Vo
11.8
11.8
11.8
11.8
8.3
4.3
0
4.1
8.4
10.2
10.2
10.2
10.2
Vin
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
Vo
11.6
11.6
8
6
4
2
0
2
4
6
8
10
12
Vin
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
Vo
5.9
5.1
4
3
2
1
0
-1
-2
-3
-4
-5
-6
B,
C,
output signal
2,
3, a, Vo= 4.3Volt
B, Vo= 8 Volt
4, a, Vo= 4.44Volt
B, Vo= 8.66Volt
5,Vo=f(Vin)
Vin
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
Vo
-10.13
-10.13
-10.13
-10.13
-8.6
-4.5
0
4.52
8.6
10.5
10.5
10.5
10.5
6,
output signal
8,
input signal
9, input signal
2*5=10volt
output signal 4.6 * 5 =23
output signal
10, output volt square wave signal from 500Hz to 50 KHz
CONCLUSION
An operational amplifier, or op-amp, is a very high gain differential amplifier with high input impedance and
low output impedance. Typical uses of the operational amplifier are to provide voltage amplitude changes
(amplitude and polarity), oscillators, filter circuits, and many types of instrumentation circuits. An op-amp
contains a number of differential amplifier stages to achieve a very high voltage gain. The operational
amplifier is an extremely efficient and versatile device. Its applications span the broad electronic industry
filling requirements for signal conditioning, special transfer functions, analog instrumentation, analog
computation, and special systems design. The analog assets of simplicity and precision characterize circuits
utilizing operational amplifiers.