Analog ICs are called linear integrated circuits because the signal output level of the circuit is a linear function of the signal input level.

1. SYLLABUS
LINEAR AND DIGITAL IC
APPLICATIONS LICA
2oEE16

7. UNIT - 1
OPERATIONAL AMPLIFIER
(OP-AMP)
LINEAR AND DIGITAL
INTEGRATED CIRCUITS
&
APPLICATIONS

8. I:IC-Classification-Features (ideal vs practical
char)- block diagram stages- Pin diagram of 741 -
inverting and non-inverting amp , differential amp,
other parameters; CMRR, slew rate.
II:DC characteristics: I/P Bias current, input offset
current, Input offset voltage, thermal drift.
AC characteristics : Freq res and stability
III:Applications: Adder, Subtractor, Multiplier,
Dividers, Integrators, Differentiators,
Instrumentation amplifier, Log & Anti-log
Amplifiers, Comparator, Schmitt trigger, Astable
multivibrator, Sample and hold circuit
CONTENTS

10. Integrated circuit (IC)
 IC : IC is a miniature (small size) , low cost electronic
equipment consisting of passive and active elements
connected together with a silicon material.
 Integrated circuit (IC), also called microelectronic circuit,
microchip, or chip.

11. BASED ON SIGNALS

12. Linear ICs Digital ICs
Linear ICs as well as analog IC. Digital ICs as well as non linear IC.
Inputs and outputs can take on a
continuous range Two possible levels low or high.
Used in aircraft, space, vehicles,
radars, PLL, Oscilloscopes etc.
in microprocessor, computers, clocks,
digital watches, calculator etc.
available as operational amplifiers[op-
amp], voltage multipliers, voltage
comparator, regulators, microwave
amplifiers Etc.
microprocessor chips, memory chips,
analog to digital chips , logic gates, flip
flops, counters, registers etc.
Its consist of very less number of
transistor as compared to digital ICs..
Its consist of more number of transistor
as compared to linear ICs.

13. CLASSIFICATION OF IC’s
Linear Digital

14. Monolithic ICs Hybrid ICs
fabricated entirely on a single
chips.
fabricated by inter- connecting a
number of individual chips.
constructed on a single piece of
silicon or other semiconductor
use mixed technology, such
as GaAs chips along with silicon
chips.
Small in size Large in size
expensive. less expensive.
Speed is high Speed is low

15. BASED ON NUMBER
OF TRANSISTORS

16. ANALOG COMPUTER

18. Vacuum tube
Transistor
IC

19. HISTORY OF OP-AMP
The term op-amp was coined in 1947 by John
R. Ragazzini
It was used in Analog computers to perform
mathematical operations such +,-,, x, hence
name given as OP-AMP
1st op-amp designed using Vacuum tubes not
popular due to bulky, power consuming and
expensive.
In 1964 alternatively developed popular 741 IC
by Dave Fullager & Robert J.Widlar at
Fairchild.
741 IC is called OP-AMP small in size , less
power consume and low cost

20. The number 741 indicates that this
operational amplifier IC has 7 active pins, 4
pins taking input and 1 output pin.

21. OPERATIONALAMPLIFIER
(Op Amp)
 Historically an Op Amp was designed to
perform such mathematical operations as
addition, subtraction, integration and
differentiation. Hence the name Operational
Amplifier.

22. ICs

24. Top 3 the largest semiconductor chip maker

25. SYMBOL…..follow me…Triangular shape & five lines

27. 236
74

28. 2
3
6
7
4

38. Whats the PIN numbers?

40. Identify the PIN numbers?

41. OPEN LOOP
NON-FEEDBACK
CLOSED LOOP
NEGATIVE FEEDBACK

42. Op-Amp Applications
With Negative feedback:
Linear applications Non linear applications
• Adders • Clippers
• Subtractors • Clampers
• Adder-Subtractor • Rectifiers
• Voltage to current converter • Peak detector
• Current to voltage converter • Sample and hold circuit
• Instrumentation amplifier • Log and antilog amplifier
• Analog computation,
Power amplifiers, etc
• Multipliers, etc.
With Positive feedback:
• Multivibrators, Oscillators, Schmitt trigger etc.
Without feedback:
• Comparators

45. Voltage Amplifier Vs Op-Amp

47. “No current flowing into either of its two inputs because high input
impedance”

49. Ideal Op Amp
 Zin = ∞
 Zout = 0
 AV = ∞
Practical Op Amp
 Zin = 2MΩ
 Zout = 100Ω
 AV = 105

51. IDEAL CHARACTERISTICS & FEATURES OF OP-AMP

52. 1. Short circuit and overload protection provided
2.Offset null Capability
3.High Gain
4.Low power consumption
5.Small in size
6.Flexibility
7.Realiability
8.Large CMRR
9.No external frequency compensation is required
10.No latch-up (no current enters)
FEATURES of IC 741 OP-AMP

54. Whether op-amp can amplify any
level? NO

58. Golden Rules of Op-Amp
1) Infinite Open Loop Gain
AOL- Open loop gain of the op-amp without feedback.
Ideal value be infinite but practical range from about 20,000 to
200,000.

59. 2) No current flowing through both
of the Inputs
I =0
I =0
There is no current flowing through either of the inputs of the op-amp because
Of high input impedance.

60. 3. Potential Difference between input pins
is ZERO by using Virtual Ground Concept
VCG.
If the non-inverting input is connected to ground , meaning
that the inverting input is also at 0V.

62. V?
What is voltage at the inverting point as shown in fig. Which
golden rule to be applicable?

63. OP-AMP WORKS
1.Inverting Amplifier
2.Non-Inverting Amplifier
3.Differential Amplifier
4.Buffer Amplifier / Voltage
follower

68. OR BUFFER AMPLIFIER
Vo=Vi

70. Virtual Ground Concept VGC: The voltage at that particular
node is almost equal to ground voltage (0V).
Virtual Ground Concept VGC

71. What is Virtual Ground Concept-VGC?
As the name indicates it is virtual, not real
ground. For some purposes we can consider it
as equivalent to ground. In op-amps the term
virtual ground means that the voltage at
that particular node is almost equal to
ground voltage (0V). It is not physically
connected to ground. It is very useful in
analysis of an op-amp when negative
feedback is employed.

72. the concept of virtual ground with inverting op-amp configuration

73. Examples -VGC

74. TERMS

76. Gain of op-amp or any amplifier is Vout/Vin.
Ad=differential mode Gain = Vout/( V1 - V2 )

77. Ac
Ad & Ac

78. Ac=0 then CMRR is infinite

82. The unit of SR is V/µsec (Volts/micro second)

85. INVERTING AMPLIFIER

86. - Sign indicates that phase shift of 1800 between input and output.

87. Applications: Used in phase shifter, integration,
signal balancing, mixer circuits etc…

88. PROBLEM

91. NON-INVERTING AMPLIFIER

92. ….3)

93. Equation 2= equation 3

94.  Used in circuits where high input impedance is
required.
 Used as a voltage follower, isolation of cascaded circuits,
to perform mathematical simulations, etc

96. NON-INVERTING AMPLIFIER
BUFFER AMPLIFIER

99. 741 Op-Amp –Internal Circuitry

103. Differential Amplifiers works under 4 modes:

110. DC and AC Characteristics

112. Thermal Drift
 Bias current, offset current and offset voltage change with temperature.
 A circuit carefully nulled at 25◦C may not remain so when the temperature
rises to 35◦C. This is called drift.
 Often, offset current drift is expressed as nA/ ◦C and offset voltage
drift in mV/ ◦C.
 These indicate the change in offset for each degree Celsius change in
temperature.
 There are very few circuit techniques that can be used to minimize the
effect of drift.
• Careful printed circuit board layout must be used to keep op-amp
away from source of heat.
• Forced air cooling may be used to stabilize the ambient temperature.