1. Op-Amp Basics & Linear Applications
Dr. S. & S.S. Gandhy
Government Engineering College
Surat
Analog Electronics
Op-Amp Basics & Linear Applications
Guided By: Prof. N.A. Gajjar

2. Prepared By: 130230109013 Gajera Marvin 130230109014 Golakiya Dushyant
Enrollment No Name
Gajera Marvin
Golakiya Dushyant
Gosai Mayur
Goswami Drashti
Hathaliya Bharat

3. Operational Amplifier+ -
Non-inverting input
Positive voltage supply
Negative voltage supply
Output
Symbol:
At a minimum, op-amps have 3 terminals: 2 input and 1 output.
An op amp also requires dc power to operate. Often, the op-amp requires both positive and negative voltage supplies (V+ and V-).

4. Basic Block Diagram V1
Level Shifting Stage
Intermediate Stage
Out put Stage
Input
Input Stage
Output V2
An Op-Amp can be conveniently divided into Four main blocks:
Input Stage
Intermediate Stage
Level Shifting Stage
Output Stage

5. Input Stage:
The input stage is Dual input, balanced output differential. The two inputs are inverting & Non-inverting input terminals. this stage provides most of the voltage gain of the op-amp and decides the input resistance value Ri
Intermediate Stage:
This is usually another differential amplifier. It is driven by the output of the input stage the stage is dual input unbalanced output differential amplifier.

6. Level Shifting Stage:
Due to direct coupling between the first two stages, the input of level shifting stage is an amplified signal with some non-zero DC level. Level shifting stage is used to bring this DC level to zero with respect to ground.
Output Stage:
This stage is normally a complementary output stage. It increases the magnitude of voltage and raises the current supplying capability of the op-amp. It also provides a low output resistance.

7. OP-AMP Pin Identification1 2 3 4 5 6 7 8
+VCC
-VEE - +
741
Notched Package
Dot marked Package

8. OP-AMP Pin Identification
Offset Null
Inverting Input
Non-Inverting Input
-VEE
Output
+VCC
N/C

9. What are These Pins?
Pin 1 and Pin 5 : Offset null input, are used to remove the Offset voltage.
Pin 2: Inverting input (-Vin), signals at this pin will be inverted at output Pin 6.
Pin 3: Non-inverting input (+Vin), signals at pin 3 will be processed without inversion.
Pin 4: Negative power supply terminal (-VEE).
Pin 6: Output (Vout) of the Op-Amp
Pin 7: Positive power supply terminal (+VCC)
Pin 8: No connection (N\C), it is just there to make it a standard 8-pin.

10. OP-AMP Terms
Op-Amp:
An active circuit element designed to perform mathematical operations of addition, subtraction, multiplication, division, differentiation and integration.
High performance linear amplifier that requires a power source to operate.
Gain:
Amount of amplification produced by an Op-Amp. Gain is independent from the supply voltage (power given for the Op-Amp to operate).

11. Open-Loop Mode:
Function of an Op-Amp when the feedback resistor (Rf) is zero. The Op-Amp operates as a comparator and not as a linear amplifier.
Comparator:
Compares the –V and +V inputs to see which is greater and returns a result.
Bandwidth:
The range of frequency at which an Op-Amp will function. (Ideal = ∞)

12. Input Offset Voltage:
Even when there is no input voltage the Op-Amp gives off a small voltage. This can be canceled out by use of the Offset Null pin on the chip.
Common Mode Rejection Ratio (CMRR):
Ability of an Op-Amp to reject a signal applied to both inputs simultaneously.
Slew Rate (V/µs):
Amount of time it takes for the Op-Amp to step to another voltage level. (Non-Ideal)

13. Typical OP-AMP Parameters
Variable
Typical Ranges
Ideal Values
Open-Loop Voltage Gain A
105 to 108 ∞
Input Resistance Ri
105 to 1013 W
∞ W
Output Resistance Ro
10 to 100 W
0 W
Supply Voltage
Vcc/V+
-Vcc/V-
5 to 30 V
-30V to 0V
N/A

14. 741 OP-AMP Maximum Ratings: Characteristics: Supply Voltage ±18 V
Power Dissipation mW
Diff. Input Voltage ±30 V
Input Voltage ±15 V
Operating Temperature 0°C to 70°C
Characteristics:
Input Offset Voltage 2 to 6 mV
Input Resistance 3 to 2 MΩ
CMMR 70 to 90 dB
Bandwidth 0.5 to 1.5 MHz
Slew Rate 0.5 V/µs
Offset
Null
Unused 1 2 3 4 5 6 7 8
- IN +
+ V -
+ IN
Out
Offset
Null
- V

15. Integrated Circuit Types
The ICs are broadly Categorized into TWO classes as:
1. Digital ICs Linear ICs
Linear ICs are equivalent of Descrete Transistor circuits such as amplifier, filters, etc.
The linear ICs are also known as the Analog ICs of all the available linear ICs almost all are operational amplifier.
We can classify the integrated circuits into TWO classes based on the technology used. The Two classes are:
1. Monolithic Technology Hybrid Technology

16. Inside an IC

17. Further Classification of IC technology is shown below.

18. Monolithic ICs:
In this type of ICs, all the circuit components, and their interactions are manufactured into or on top of a single chip of Silicon. that is why the name monolithic.
The technology is ideally suitable when identical circuits are required in a very large number.
The monolithic circuits are further classified into TWO categories namely “Bipolar” & “Unipolar”.
The advantages of monolithic technology are:
1. Low per unit cost 2. Very high reliability

19. Classification based on Active devices:
Hybrid ICs:
The hybrid circuits are completely different from the monolithic ones.
In hybrid circuits, separate component parts are first attached to a Ceramic substrate. Then these parts are interconnected by means of either metallization pattern or wire bonds to form the circuits.
Classification based on Active devices:
Depending upon the type of active device being used, the ICs can be classified as Bipolar ICs (which use bipolar junction transistor) and Unipolar ICs (which use field effect transistors).
The bipolar and Unipolar ICs are further classified depending on the isolation technique or type of FET (JFET or MOSFET)

20. Linear Applications of OP-AMP
There are many applications of an OP-AMP.
Voltage Adder (Summing Amplifier)
Difference Amplifier
Integrator
Differentiator
Voltage Follower & etc…

21. Voltage Adder (Summing Amplifier)
Application : For Noise Cancellation

22. Difference Amplifier
If R1 = R2 and Rf = Rg:

23. Integrator R C
Vin Vo
The input is integrated with respect to time.

24. Differentiator R2 R1
Vin Vo C R3

25. Voltage Follower It is a non inverting amplifier with gain=1
Vin
It is a non inverting amplifier with gain=1
So the output is the same as input.

26. And That’s It…