ECCF Experiment No.9 - Opamp integrator Differentiator PDF

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FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING (CRCE) Department of Computer Engineering (CE)

9. OPERATIONAL AMPLIFIER APPLICATIONS 1.

Course, Subject & Experiment Details

Academic Year 2018 – 2019 Course & Semester S.E. (COMP) – Sem. III

Estimated Time Experiment No.9– 02 Hours Subject Name Basic Electronics Lab Operational Amplifier as Chapter No. & Unit 03 – Unit 3.5 Mapped with CO-2 Chapter Title Integrator & Differentiator Experiment Type Hardware (Bread Board) Subject Code CSL 302 2.

Aim & Objective of Experiment

The experiment aims to introduce students to study operational amplifier (op-amp) & study their applications. The objective to be achieved is to design & use the op-amp for given set of specification for implementing practical applications such as adder subtractor integrators & differentiators. 3.

Expected Outcomes of Experiment ฀ Understanding mathematical model (ideal & practical) of Integrator as well as Differentiator ฀ Open Loop & Closed Loop configurations of the operational amplifier (op-amp)

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Brief Theoretical Description

(a) •

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Integrator: An integrator is a device to perform the mathematical operation known as integration, a fundamental operation in calculus. The integration function is often part of engineering and scientific calculations. Electronic analog integrators were the basis of analog computers. The gain of an integrator at low frequency is very high and the circuit goes to saturation. The feedback capacitor is shunted with a resistor in the practical integrator to overcome the above problem. The practical integrator is known as lossy integrator.

Basic Electronics Lab (BEL) – CSL 302

S.E. (COMP) – Semester III for Academic Year 2018 – 2019

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FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING (CRCE) Department of Computer Engineering (CE) The circuit can be analyzed by applying Kirchhoff's current law at the node v2, keeping ideal opamp behavior in mind

Ii= Ib+If Ib =0 in ideal Op-amp

I1=If Furthermore, the capacitor has a voltage-current relationship governed by the equation:  Ic - C  Substituting the appropriate variables:  − 2 (2 − ) =   1

V2=V1 = 0 in an ideal Op-Amp

Vo = (b) •

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 

  ()

Differentiator: A Differentiator is a circuit that is designed such that the output of the circuit is proportional to the time derivative of the input. The basic Differentiator Amplifier circuit is the exact opposite to that of the Integrator operational amplifier, the position of the capacitor and resistor have been reversed and now the Capacitor, C is connected to the input terminal of the inverting amplifier while the Resistor, R1 forms the negative feedback element across the operational amplifier.

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This circuit performs the mathematical operation of Differentiation that is it produces a voltage output which is proportional to the input voltage's rate-of-change and the current flowing through the capacitor

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The capacitor blocks any DC content only allowing AC type signals to pass through and whose frequency is dependent on the rate of change of the input signal. At low frequencies the reactance of the capacitor is "High" resulting in a low gain (R1/Xc) and low output voltage

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from the op-amp. Problems in an Ordinary op-amp differentiator are instability and high frequency noise. A Resistor is added in series with the capacitor at the input and a capacitor is added in parallel to the resistor in the feedback circuit in the practical differentiator to eliminate the above problems.  Vo= - R1Cf  () Basic Electronics Lab (BEL) – CSL 302

S.E. (COMP) – Semester III for Academic Year 2018 – 2019

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FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING (CRCE) Department of Computer Engineering (CE) 5.

Practical Circuit Diagram & Hardware Setup Integrator:

Fig No -1 Differentiator:

Fig No -2 6

Components Required for Integrator & Differentiator

Type of Components Resistors

Op- Amps

Symbolic Notations R1 R2 R1 C1/ Cf A1

Component Value & Specifications 47 k, ¼ W 10 k, ¼ W 4.7 k, 0.01 µf IC 741C

Basic Electronics Lab (BEL) – CSL 302

S.E. (COMP) – Semester III for Academic Year 2018 – 2019

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FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING (CRCE) Department of Computer Engineering (CE) 7

Experimental Procedure

INTEGRATOR: 1. Connect the circuit as shown in fig 1. 2. Apply a symmetrical square wave of 2Vp-p amplitude and 10 KHz frequency. 3. Connect the input and output of the circuit to channel 1 and channel 2 of the CRO respectively and observe the waveforms. 4. Draw the waveforms along with the levels on a graph. 5. Compare the practical values with theoretical values. 6. Repeat the same for sine-wave. DIFFERENTIATOR: 1. Connect the circuit as shown in fig 2. 2. Apply a symmetrical triangular wave of 2Vp-p amplitude and 1 KHz frequency. 3. Connect the input and output of the circuit to channel 1and channel 2 of the CRO respectively and observe the waveforms. 4. Draw the waveforms along with the levels on a graph. 5. Compare the practical values with theoretical values. 6. Repeat the same for the sine-wave.

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Observation Table for Integrator Expected Output Actual Output waveform Waveform

Sr.No

Input Waveform

1

Square Wave(10KHz)

1 ms

2 VPP

Triangular Wave

2

Sine wave (10KHz)

1ms

2 VPP

Cosine Wave

Frequency Amplitude

Observation Table for Differentiator Sr.No 1 2

Input Waveform Square Wave(1KHz) Triangular Wave (1KHz)

Frequency Amplitude

Expected Output Actual Output Waveform Waveform

1 ms

2 VPP

Spike

1ms

2 VPP

Square Wave

Basic Electronics Lab (BEL) – CSL 302

S.E. (COMP) – Semester III for Academic Year 2018 – 2019

4

FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING (CRCE) Department of Computer Engineering (CMPN)

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Conclusions & Inferences Students should explain in brief the concluded outcome from the experiment & its inference, as obtained from the observation table & the nature of the graph which explains the circuit behavior

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Practical & Real Life Applications ฀ ฀ ฀ ฀ ฀ ฀ ฀

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Analog amplifiers, attenuators, buffers & drivers Analog Signal Processing & Wave Shaping Techniques Analog to Digital & Digital to Analog Converters (ADC & DAC) Voltage Regulators & DC Power Supplies Oscillators & Waveform Generators Filters & Timers Analog Computation & Mathematical Operations Post Lab & Reference Questions 1.

Obtain Mathematical Expression for OP-Amp as an Integrator.

2.

Obtain Mathematical Expression for OP-Amp as a Differentiator.

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Basic Electronics Lab (BEL) – CSL 302

S.E. (COMP) – Semester III for Academic Year 2018 – 2019

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