dnarenderreddy
Junior Member level 2
augmenting integrator
caontains applications of opamps
contents:
INTRODUCTION...................................................................................................................................7
Computation Control Instrumentation .............................................................................................7
The Feedback Technique ...............................................................................................................7
Notation and Terminology...............................................................................................................8
Input Terminals..............................................................................................................................9
Output Terminals ............................................................................................................................9
Power Connections ......................................................................................................................10
Summary of Notation....................................................................................................................10
Electrical Circuit Models ...............................................................................................................10
Circuit Notation............................................................................................................................11
The Ideal Operational Amplifier ....................................................................................................12
Defining the Ideal Operational Amplifier........................................................................................12
A Summing Point Restraint...........................................................................................................13
CIRCUITS AND ANALYSES USING THE IDEAL OPERATIONAL AMPLIFIER.................................14
The Desirability of Feedback ........................................................................................................14
Two Important Feedback Circuits .................................................................................................15
Voltage Follower..........................................................................................................................15
Non-Inverting Amplifier .................................................................................................................17
INVERTING AMPLIFIER ..............................................................................................................18
Intuitive Analysis Techniques........................................................................................................19
Current Output.............................................................................................................................20
Reactive Elements.......................................................................................................................20
Integrator .....................................................................................................................................21
Differentiator................................................................................................................................21
Voltage Adder..............................................................................................................................23
Scaling Summer ...........................................................................................................................23
Combining Circuit Functions .........................................................................................................24
Differential Input Amplifier.............................................................................................................24
Balanced Amplifier.......................................................................................................................25
Ideal-Real Comparison.................................................................................................................27
CHARACTERISTICS OF PRACTICAL OPERATIONAL AMPLIFIERS...............................................29
Open Loop Characteristics ...........................................................................................................29
Open Loop Operation ...................................................................................................................30
Output Limiting .............................................................................................................................30
FREQUENCY DEPENDENT PROPERTIES ........................................................................................31
Introduction..................................................................................................................................31
Open Loop Gain and the Bode Plot ..............................................................................................31
Bode Plot Construction.................................................................................................................31
Closed Loop Gain.........................................................................................................................32
Stability........................................................................................................................................33
Compensation ..............................................................................................................................33
Compensation Changes ...............................................................................................................34
Bandwidth....................................................................................................................................35
Loop Gain....................................................................................................................................35
The Significance of Loop Gain......................................................................................................36
BODE PLOTS AND BASIC PRACTICAL CIRCUITRY........................................................................37
Voltage Follower..........................................................................................................................37
SBOA092A
4 HANDBOOK OF OPERATIONAL AMPLIFIER APPLICATIONS
Inverter ........................................................................................................................................ 37
X1000 Amplifier ............................................................................................................................ 38
Differentiator................................................................................................................................ 38
INTEGRATOR............................................................................................................................. 40
OTHER IMPORTANT PROPERTIES OF OPERATIONAL AMPLIFIERS............................................ 41
Summing Point Restraints ............................................................................................................ 41
Closed Loop Impedance Levels.................................................................................................... 42
Output Impedance....................................................................................................................... 42
Input Impedance.......................................................................................................................... 43
Differential Inputs and Common Mode Rejection.......................................................................... 44
The Common Mode Voltage Limit ................................................................................................ 44
Offset........................................................................................................................................... 44
Drift 45
Capacitive Loading....................................................................................................................... 45
VOLTAGE DETECTORS AND COMPARATORS ............................................................................... 46
Voltage Limiting Operational Amplifiers ........................................................................................ 46
THE VOLTAGE FOLLOWER .............................................................................................................. 49
BUFFERS AND ISOLATION AMPLIFIERS .................................................................................. 50
Inverting Buffer Adjustable Gain ................................................................................................... 50
Balanced Output.......................................................................................................................... 50
VOLTAGE AND CURRENT REFERENCES........................................................................................ 50
Isolated Standard Cell .................................................................................................................. 51
Constant Current Generator ......................................................................................................... 51
Buffer Variation............................................................................................................................ 52
Presettable Voltage Source .......................................................................................................... 52
Reference Voltage Supply ............................................................................................................ 52
THE NON-INVERTING AMPLIFIER ....................................................................................................53
THE INVERTING AMPLIFIER ............................................................................................................. 54
INTEGRATORS.................................................................................................................................. 55
PRACTICAL INTEGRATORS.............................................................................................................. 55
Simple Integrators ........................................................................................................................ 56
Summing Integrator ...................................................................................................................... 58
Double Integrator......................................................................................................................... 58
Differential Integrator .................................................................................................................... 59
AC Integrator ............................................................................................................................... 59
Augmenting Integrator .................................................................................................................. 59
DIFFERENTIATORS........................................................................................................................... 61
With “Stop” .................................................................................................................................. 61
Low Noise ................................................................................................................................... 62
Augmented Differentiator.............................................................................................................. 62
THE VOLTAGE SUMMER................................................................................................................... 63
SUMMING AND AVERAGING AMPLIFIERS................................................................................ 64
Adder........................................................................................................................................... 64
Scaling Adder.............................................................................................................................. 64
Direct Addition............................................................................................................................. 65
Averager...................................................................................................................................... 65
Weighted Average........................................................................................................................ 66
THE DIFFERENTIAL INPUT AMPLIFIER............................................................................................ 67
Adder-Subtractor or Floating Input Combiner ............................................................................... 68
SBOA092A
HANDBOOK OF OPERATIONAL AMPLIFIER APPLICATIONS 5
THE DIFFERENTIAL (BALANCED) OUTPUT AMPLIFIER.................................................................69
DC AMPLIFIERS ................................................................................................................................70
Simple Inverting sign changing amplifier.......................................................................................70
Chopper Stabilized .......................................................................................................................70
Simple Gain Control......................................................................................................................70
Linear Gain Control ......................................................................................................................71
Simple Non-Inverting ....................................................................................................................71
Power Booster.............................................................................................................................71
Differential Output.........................................................................................................................73
Gain Control ................................................................................................................................73
Inverting Gain Control...................................................................................................................73
DIFFERENTIAL AMPLIFIERS......................................................................................................74
Subtractor....................................................................................................................................74
Difference Amplifier ......................................................................................................................74
Common Mode Rejection .............................................................................................................75
Differential Input-Output................................................................................................................75
AC AMPLIFIERS ................................................................................................................................76
DC Amplifiers with Blocking Capacitors ........................................................................................76
Simple Amplifier .....................................................................................................................................76
Single Supply .........................................................................................................................................76
Non-Inverting ..........................................................................................................................................77
Double Rolloff.........................................................................................................................................77
AC Preamplifier ......................................................................................................................................78
CURRENT OUTPUT DEVICES............................................................................................................79
Feedback Loop............................................................................................................................79
Simple Meter Amplifier..................................................................................................................79
Meter Amplifier .............................................................................................................................80
Current Injector............................................................................................................................80
Linear Current Source ..................................................................................................................81
Deflection Coil Driver ....................................................................................................................82
OSCILLATORS AND MULTI VIBRATORS .........................................................................................83
Simple Oscillator..........................................................................................................................83
Wien Bridge Oscillator ..................................................................................................................83
PHASE LEAD AND LAG NETWORKS ...............................................................................................84
Lag Element ................................................................................................................................84
Adjustable Lag.............................................................................................................................84
Lag value linear with R setting......................................................................................................85
Adjustable Lead...........................................................................................................................85
Lead-Lag .....................................................................................................................................86
Time Delay ..................................................................................................................................86
ADDITIONAL CIRCUITS .....................................................................................................................87
Absolute Value .............................................................................................................................87
Peak Follower..............................................................................................................................87
Precision Rectifier........................................................................................................................88
AC to DC Converter......................................................................................................................88
Full Wave Rectifier .......................................................................................................................89
Rate Limiter .................................................................................................................................89
Time Delay ..................................................................................................................................90
Selective Amplifier ........................................................................................................................91
SECTION III: SELECTING THE PROPER OPERATIONAL AMPLIFIER ...........................................92
SBOA092A
6 HANDBOOK OF OPERATIONAL AMPLIFIER APPLICATIONS
Focus on Limiting Specifications................................................................................................... 92
Avoid Closed Loop vs. Open Loop Confusion............................................................................... 92
Selection Check List ..................................................................................................................... 92
Assistance Available from Texas Instruments............................................................................... 93
References....................................................................
caontains applications of opamps
contents:
INTRODUCTION...................................................................................................................................7
Computation Control Instrumentation .............................................................................................7
The Feedback Technique ...............................................................................................................7
Notation and Terminology...............................................................................................................8
Input Terminals..............................................................................................................................9
Output Terminals ............................................................................................................................9
Power Connections ......................................................................................................................10
Summary of Notation....................................................................................................................10
Electrical Circuit Models ...............................................................................................................10
Circuit Notation............................................................................................................................11
The Ideal Operational Amplifier ....................................................................................................12
Defining the Ideal Operational Amplifier........................................................................................12
A Summing Point Restraint...........................................................................................................13
CIRCUITS AND ANALYSES USING THE IDEAL OPERATIONAL AMPLIFIER.................................14
The Desirability of Feedback ........................................................................................................14
Two Important Feedback Circuits .................................................................................................15
Voltage Follower..........................................................................................................................15
Non-Inverting Amplifier .................................................................................................................17
INVERTING AMPLIFIER ..............................................................................................................18
Intuitive Analysis Techniques........................................................................................................19
Current Output.............................................................................................................................20
Reactive Elements.......................................................................................................................20
Integrator .....................................................................................................................................21
Differentiator................................................................................................................................21
Voltage Adder..............................................................................................................................23
Scaling Summer ...........................................................................................................................23
Combining Circuit Functions .........................................................................................................24
Differential Input Amplifier.............................................................................................................24
Balanced Amplifier.......................................................................................................................25
Ideal-Real Comparison.................................................................................................................27
CHARACTERISTICS OF PRACTICAL OPERATIONAL AMPLIFIERS...............................................29
Open Loop Characteristics ...........................................................................................................29
Open Loop Operation ...................................................................................................................30
Output Limiting .............................................................................................................................30
FREQUENCY DEPENDENT PROPERTIES ........................................................................................31
Introduction..................................................................................................................................31
Open Loop Gain and the Bode Plot ..............................................................................................31
Bode Plot Construction.................................................................................................................31
Closed Loop Gain.........................................................................................................................32
Stability........................................................................................................................................33
Compensation ..............................................................................................................................33
Compensation Changes ...............................................................................................................34
Bandwidth....................................................................................................................................35
Loop Gain....................................................................................................................................35
The Significance of Loop Gain......................................................................................................36
BODE PLOTS AND BASIC PRACTICAL CIRCUITRY........................................................................37
Voltage Follower..........................................................................................................................37
SBOA092A
4 HANDBOOK OF OPERATIONAL AMPLIFIER APPLICATIONS
Inverter ........................................................................................................................................ 37
X1000 Amplifier ............................................................................................................................ 38
Differentiator................................................................................................................................ 38
INTEGRATOR............................................................................................................................. 40
OTHER IMPORTANT PROPERTIES OF OPERATIONAL AMPLIFIERS............................................ 41
Summing Point Restraints ............................................................................................................ 41
Closed Loop Impedance Levels.................................................................................................... 42
Output Impedance....................................................................................................................... 42
Input Impedance.......................................................................................................................... 43
Differential Inputs and Common Mode Rejection.......................................................................... 44
The Common Mode Voltage Limit ................................................................................................ 44
Offset........................................................................................................................................... 44
Drift 45
Capacitive Loading....................................................................................................................... 45
VOLTAGE DETECTORS AND COMPARATORS ............................................................................... 46
Voltage Limiting Operational Amplifiers ........................................................................................ 46
THE VOLTAGE FOLLOWER .............................................................................................................. 49
BUFFERS AND ISOLATION AMPLIFIERS .................................................................................. 50
Inverting Buffer Adjustable Gain ................................................................................................... 50
Balanced Output.......................................................................................................................... 50
VOLTAGE AND CURRENT REFERENCES........................................................................................ 50
Isolated Standard Cell .................................................................................................................. 51
Constant Current Generator ......................................................................................................... 51
Buffer Variation............................................................................................................................ 52
Presettable Voltage Source .......................................................................................................... 52
Reference Voltage Supply ............................................................................................................ 52
THE NON-INVERTING AMPLIFIER ....................................................................................................53
THE INVERTING AMPLIFIER ............................................................................................................. 54
INTEGRATORS.................................................................................................................................. 55
PRACTICAL INTEGRATORS.............................................................................................................. 55
Simple Integrators ........................................................................................................................ 56
Summing Integrator ...................................................................................................................... 58
Double Integrator......................................................................................................................... 58
Differential Integrator .................................................................................................................... 59
AC Integrator ............................................................................................................................... 59
Augmenting Integrator .................................................................................................................. 59
DIFFERENTIATORS........................................................................................................................... 61
With “Stop” .................................................................................................................................. 61
Low Noise ................................................................................................................................... 62
Augmented Differentiator.............................................................................................................. 62
THE VOLTAGE SUMMER................................................................................................................... 63
SUMMING AND AVERAGING AMPLIFIERS................................................................................ 64
Adder........................................................................................................................................... 64
Scaling Adder.............................................................................................................................. 64
Direct Addition............................................................................................................................. 65
Averager...................................................................................................................................... 65
Weighted Average........................................................................................................................ 66
THE DIFFERENTIAL INPUT AMPLIFIER............................................................................................ 67
Adder-Subtractor or Floating Input Combiner ............................................................................... 68
SBOA092A
HANDBOOK OF OPERATIONAL AMPLIFIER APPLICATIONS 5
THE DIFFERENTIAL (BALANCED) OUTPUT AMPLIFIER.................................................................69
DC AMPLIFIERS ................................................................................................................................70
Simple Inverting sign changing amplifier.......................................................................................70
Chopper Stabilized .......................................................................................................................70
Simple Gain Control......................................................................................................................70
Linear Gain Control ......................................................................................................................71
Simple Non-Inverting ....................................................................................................................71
Power Booster.............................................................................................................................71
Differential Output.........................................................................................................................73
Gain Control ................................................................................................................................73
Inverting Gain Control...................................................................................................................73
DIFFERENTIAL AMPLIFIERS......................................................................................................74
Subtractor....................................................................................................................................74
Difference Amplifier ......................................................................................................................74
Common Mode Rejection .............................................................................................................75
Differential Input-Output................................................................................................................75
AC AMPLIFIERS ................................................................................................................................76
DC Amplifiers with Blocking Capacitors ........................................................................................76
Simple Amplifier .....................................................................................................................................76
Single Supply .........................................................................................................................................76
Non-Inverting ..........................................................................................................................................77
Double Rolloff.........................................................................................................................................77
AC Preamplifier ......................................................................................................................................78
CURRENT OUTPUT DEVICES............................................................................................................79
Feedback Loop............................................................................................................................79
Simple Meter Amplifier..................................................................................................................79
Meter Amplifier .............................................................................................................................80
Current Injector............................................................................................................................80
Linear Current Source ..................................................................................................................81
Deflection Coil Driver ....................................................................................................................82
OSCILLATORS AND MULTI VIBRATORS .........................................................................................83
Simple Oscillator..........................................................................................................................83
Wien Bridge Oscillator ..................................................................................................................83
PHASE LEAD AND LAG NETWORKS ...............................................................................................84
Lag Element ................................................................................................................................84
Adjustable Lag.............................................................................................................................84
Lag value linear with R setting......................................................................................................85
Adjustable Lead...........................................................................................................................85
Lead-Lag .....................................................................................................................................86
Time Delay ..................................................................................................................................86
ADDITIONAL CIRCUITS .....................................................................................................................87
Absolute Value .............................................................................................................................87
Peak Follower..............................................................................................................................87
Precision Rectifier........................................................................................................................88
AC to DC Converter......................................................................................................................88
Full Wave Rectifier .......................................................................................................................89
Rate Limiter .................................................................................................................................89
Time Delay ..................................................................................................................................90
Selective Amplifier ........................................................................................................................91
SECTION III: SELECTING THE PROPER OPERATIONAL AMPLIFIER ...........................................92
SBOA092A
6 HANDBOOK OF OPERATIONAL AMPLIFIER APPLICATIONS
Focus on Limiting Specifications................................................................................................... 92
Avoid Closed Loop vs. Open Loop Confusion............................................................................... 92
Selection Check List ..................................................................................................................... 92
Assistance Available from Texas Instruments............................................................................... 93
References....................................................................
