Introduction to operational Amplifier. For A2 level physics (CIE). Discusses characteristics of op amp, inverting and non inverting amplifier, and voltage follower, and transfer characetristics, virtual earth , etc

1. Operational Amplifier Part 1 Mukesh N Tekwani tekwani@ email.com

4. Internal Block Diagram

9. Op Amp Slew Rate Explained

16. The Basic Inverting Amplifier R 2 V in – + + – V out R 1 + – I 1 I 2 Resistor used to control amplification

21. KCL

24. Transfer Characteristics of Inverting Amplifier V o -V s +V s saturation saturation Vin B A

25. Transfer Characteristics of a Non-inverting Amplifier V o -V s +V s saturation saturation V 2 – V 1 V 2 > V 1 V 2 < V 1 B A

27. Transfer Characteristics of an OpAmp V s -V s V o Value V 0 might have for an ac i/p if opamp did not saturate

29. Saturation Effect in Op Amp Suppose gain is -10. Assume the input is a signal of amplitude of 1.4v. We would expect the output of the amplifier to be a signal of amplitude of 14V because the amplitude of the input is 1.4v and the gain is -10. But, if you take saturation into account, you will get a signal that is &quot;flattened&quot; at the top and bottom.

33. Problem 3:

36. Concept of virtual earth R 2 V in P Q – + + – V out R 1 + – I 1 I 2 V Q V P

38. Non-inverting Amplifier

39. Non-inverting op amp – + V i V o R f R i

41. Voltage Follower – + V i V o

44. Voltage Follower used for measuring charge ? Test Plate

46. Thank You