1. J.-B. Seo, S. Srirangarajan, S.-D. Roy, and S. Janardhanan
Course Instructors:
J.-B. Seo, S. Srirangarajan, S.-D. Roy, and S. Janardhanan
Department of Electrical Engineering, IITD

2. Operational Amplifier (741-type)⑦ ② ⑥ ③ ④

3. Operational Amplifier (741-type)⑦ ② ⑥ ③ ④

4. Operational Amplifier (741-type)⑦ ② ① ④ ③ ② ⑥ ③ ④

5. Operational Amplifier (741-type)⑦ ② ① ④ ③ ② ⑥ ③ ④

6. Operational Amplifier (741-type)

7. Operational Amplifier (741-type)
 It consists of five major functional blocks
Current mirror

8. Operational Amplifier (741-type)
 It consists of five major functional blocks
Current mirror
Differential amplifier

9. Operational Amplifier (741-type)
 It consists of five major functional blocks
Current mirror
Differential amplifier
Class A gain stage

10. Operational Amplifier (741-type)
 It consists of five major functional blocks
Current mirror
Differential amplifier
Class A gain stage
Voltage level shifter

11. Operational Amplifier (741-type)
 It consists of five major functional blocks
Current mirror
Differential amplifier
Class A gain stage
Voltage level shifter
Output stage (Class AB Amp.)

12. Characteristic of an Ideal Op-Amp

13. Analog invert(er) amp.
(Infinite resistance at input for ideal op-amp )

14. Analog invert(er) amp.
(Infinite resistance at input for ideal op-amp )

15. Analog invert(er) amp.
(Infinite resistance at input for ideal op-amp )

16. Analog invert(er) amp.
(Infinite resistance at input for ideal op-amp )

17. Recall the voltage gain for ideal op-amp
Analog invert(er) amp.
(Infinite resistance at input for ideal op-amp )
Recall the voltage gain for ideal op-amp

18. - Recall the voltage gain for ideal op-amp
Analog invert(er) amp.
(Infinite resistance at input for ideal op-amp )
- Recall the voltage gain for ideal op-amp

19. - Recall the voltage gain for ideal op-amp
Analog invert(er) amp.
(Infinite resistance at input for ideal op-amp )
- Recall the voltage gain for ideal op-amp

20. Non-inverting Circuit (p.88)

21. Non-inverting Circuit (p.88)
— ①
For ideal op-amp,
— ②
Combining ① and ②, we have

22. Non-inverting Circuit (p.88)
— ①
For ideal op-amp,
— ②
Combining ① and ②, we have

23. Non-inverting Circuit (p.88)
— ①
For ideal op-amp,
— ②
Combining ① and ②, we have

24. Non-inverting Circuit (p.88)
— ①
For ideal op-amp,
— ②
Combining ① and ②, we have

25. Non-inverting Circuit (p.88)
— ①
For ideal op-amp,
— ②
Combining ① and ②, we have

26. Analysis Circuit with ideal Op-Amp

27. Analysis Circuit with ideal Op-Amp

28. Analysis Circuit with ideal Op-Amp
For inverting Op-Amp,

29. Analysis Circuit with ideal Op-Amp
For inverting Op-Amp,
For non-inverting Op-Amp,

30. Summing Circuit (p.88)

31. Practical Op-Amp: Slew rate
For SR= , find the frequency of the square wave pulse, where the output will be triangular wave with peak voltage of 4V.

32. Practical Op-Amp: Slew rate
For SR= , find the frequency of the square wave pulse, where the output will be triangular wave with peak voltage of 4V.

33. Practical Op-Amp: Slew rate
For SR= , find the frequency of the square wave pulse, where the output will be triangular wave with peak voltage of 4V.

34. Practical Op-Amp: Slew rate
If the required output for the op-amp is 20 kHz sine-wave signal with 10 V peak voltage. Find the minimum acceptable slew rate for the op-amp.

35. Practical Op-Amp: Slew rate
If the required output for the op-amp is 20 kHz sine-wave signal with 10 V peak voltage. Find the minimum acceptable slew rate for the op-amp.

36. Practical Op-Amp: Slew rate
If the required output for the op-amp is 20 kHz sine-wave signal with 10 V peak voltage. Find the minimum acceptable slew rate for the op-amp.

37. Example

38. Example

39. Example

40. Example

41. Example

42. Voltage follower circuit:
Why do we need?
Voltage delivered to the load:
LOAD

43. Voltage follower circuit:
Why do we need?
Voltage delivered to the load: + —
LOAD

44. Low Pass Filter

45. Low Pass Filter

46. Low Pass Filter
- KCL gives

47. Low Pass Filter
- KCL gives

48. Low Pass Filter
- KCL gives
- Magnitude of voltage gain:

49. Low Pass Filter

50. Cascade Low Pass Filter

51. Cascade Low Pass Filter

52. Cascade Low Pass Filter

53. Cascade Low Pass Filter
The magnitude is

54. Summing Application: Digital to Analog Converter (DAC)
 Convert a digital binary number to the corresponding analog signal

55. Summing Application: Digital to Analog Converter (DAC)
 Convert a digital binary number to the corresponding analog signal v1 v2 v3 v4 R1 R2 R3 R4

56. Summing Application: Digital to Analog Converter (DAC)
 Convert a digital binary number to the corresponding analog signal v1 v2 v3 v4 R1 R2 R3 R4

57. Summing Application: Digital to Analog Converter (DAC)
 Convert a digital binary number to the corresponding analog signal v1 v2 v3 v4 R1 R2 R3 R4

58. Summing Application: Digital to Analog Converter (DAC)
 Convert a digital binary number to the corresponding analog signal v1 v2 v3 v4 R1 R2 R3 R4

59. R-2R Ladder of OP Amp DAC
For accurate conversion, the inputs to a summing-circuit DAC would have to be precisely known voltages, a condition that is not required in digital systems.
In practice, the R-2R ladder (as shown in fig. ) is far superior.

60. R-2R Ladder of OP Amp DAC

61. R-2R Ladder of OP Amp DAC

62. R-2R Ladder of OP Amp DAC

63. R-2R Ladder of OP Amp DAC

64. R-2R Ladder of OP Amp DAC

65. R-2R Ladder of OP Amp DAC

66. R-2R Ladder of OP Amp DAC

67. R-2R Ladder of OP Amp DAC

68. R-2R Ladder of OP Amp DAC

69. R-2R Ladder of OP Amp DAC
This circuit provides the desired conversion using only two resistance values

70. Example

71. Example

72. Example

73. Example

74. Example

75. Differential Amplifier

76. Differential Amplifier

77. Differential Amplifier

78. Differential Amplifier

79. Differential Amplifier

80. Differential Amplifier

81. Differential Amplifier
Combining the above two equations yields

82. Differential Amplifier
Combining the above two equations yields

83. Differential Amplifier
Combining the above two equations yields

84. Differential Amplifier
Combining the above two equations yields
 0

85. Example

86. Example

87. Example

88. Example

89. Example

90. Practical Op-Amp: Common mode rejection ratio (CMRR)
(ideal op-amp)
(practical op-amp)
(practical op-amp)

91. Practical Op-Amp: Common mode rejection ratio (CMRR)