1. 1.6 Op-Amp Basics Basic Op-Amp Practical (Ri = high , Ro = small)
Op-amp equivalent circuit
Practical (Ri = high , Ro = small)
Ideal (Ri =∞ , Ro = 0)

2. 1.6 Op-Amp Basics Basic Operation of Op-Amp
input voltage at minus (-) output voltage opposite in phase
input voltage at plus (+) output voltage in phase
Basic Op-Amp - Constant-gain multiplier
Input signal is applied through resistor Ri to the minus input
Output is connected to the same minus input through resistor Rf
Resulting output: opposite in phase to input signal
Inverting constant gain multiplier

3. 1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier
Op-amp ac equivalent circuit

4. 1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier
Redrawn equivalent circuit
(for circuit analysis)
Ideal Op-amp equivalent circuit

5. 1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier
Using Superposition theorem
i) V1 only (set –AvVi =0)
ii) –AvVi only (set V1 =0)

6. 1.6 Op-Amp Basics Basic Op-Amp - Constant-gain multiplier
It is shown that the ratio i/o depends only on the value of Rf and R1

7. 1.6 Op-Amp Basics Basic Op-Amp - Unity Gain
If Rf = R1
Gain with negative sign shows that the output voltage has undergone 180º phase inversion from input signal
Basic Op-Amp - Constant Gain
If Rf = 10R1
If we select precise values for Rf and Ri, we can obtain a wide range of gains
Gain accuracy depends on resistors used
Gain is slightly affected by temperature & other circuit factors

8. 1.7 Practical Op Amp Circuits
Inverting Amplifier
Non-inverting Amplifier
Inverting constant gain multiplier
Non-inverting constant gain multiplier

9. 1.7 Practical Op Amp Circuits
Non-inverting Amplifier
Non-inverting constant-gain multiplier
Equivalent circuit
Since Vi = 0, using voltage divider rule,
Which results in;

10. 1.8 Data Sheet LM741

11. 1.8 Data Sheet LM741 ABSOLUTE MAXIMUM RATINGS Supply voltage = +22V
Internal power dissipation = 500mW
Differential input voltage = + 30V
Input voltage = + 15V
ELECTRICAL CHARACTERISTICS
Input offset voltage
Input offset current
Input bias current
Input resistance

12. 1.8 Data Sheet LM741 ELECTRICAL CHARACTERISTICS
Large signal voltage gain
Output voltage swing
Output short circuit current
Supply voltage rejection ratio
Bandwidth
Slew rate
Supply current
Power consumption

13. 1.8 Data Sheet LM741

14. 1.8 Data Sheet LM741

15. 1.8 Data Sheet LM741