Analog Circuit Design (eBook)

Cover 1
Analog Circuit Design 4
Copyright 5
Dedication 6
Contents 10
Acknowledgments 14
Introduction 15
Publisher’s Note 12
Foreword 17
Part 
18 
Section 1 -Power Management Tutorials 20
1 -Ceramic input capacitors cancause overvoltage transients 21
Plug in the wall adapter at your own risk 21
Building the Test Circuit 21
Turning on the switch 22
Testing a portable application 22
Input voltage transients with different input elements 22
Optimizing Input Capacitors 23
Conclusion 23
2 -Minimizing switching regulator residue in linear regulator outputs 24
Introduction 24
Switching regulator AC output content 24
Ripple and spike rejection 25
Ripple/spike simulator 28
Linear regulator high frequency rejection evaluation/optimization 29
References 31
3 -Power Conditioning for notebook and palmtop systems 35
Introduction 35
LT1432 driver for high efficiency 5V and 3.3V buck regulato 
35 
Circuit description 36
BICMOS switching regulator family provides highest step-down efficiencies 37
Surface mount capacitors for switching regulator applications 39
High efficiency linear supplies 39
Power switching with dual high side micropower N-channel MOSFET drivers 40
LT1121 micropower 150mA regulator with shutdown 41
Cold cathode fluorescent display driver 41
Battery charging 42
Lead acid battery charger 42
NiCAD charging 43
LCD display contrast power supply 44
A 4-cell NiCad regulator/charger 44
Power supplies for palmtop computers 47
2-Cell input palmtop power supply.circuits 48
LCD bias from 2 AA cells 48
4-Cell input palmtop power supply.circuits 48
A CCFL backlight driver for palmtop.machines 51
4 -2-Wire virtual remote sensing for voltage regulators 52
Introduction 52
"Virtual" remote sensing 52
Applications 53
VRS linear regulators 53
VRS equipped switching regulators 55
VRS based isolated switching supplies 55
VRS halogen lamp drive circuit 62
References 62
Appendix A 
66 
Section 2 -Switching Regulator Design 74
5 -LT1070 design manual 76
Introduction 76
Preface 77
Smaller versions of the LT1070 77
Inductance calculations 77
Protecting the magnetics 78
New switch current specification 78
High supply voltages 78
Discontinuous & ldquo
LT1070 operation 79
Pin functions 80
Input supply (VIN) 80
Ground pin 80
Feedback pin 80
Compensation pin (Vc) 82
Output pin 83
Basic switching regulator topologies 84
Buck converter 84
Boost regulators 85
Combined buck-boost regulator 86
'Cuk converter 86
Flyback regulator 86
Forward converter 87
Current-boosted boost converter 87
Current-boosted buck converter 87
Application circuits 88
Boost mode (output voltage higher than input) 88
Inductor 89
Output capacitor 90
Frequency compensation 90
Current steering diode 90
Short-circuit conditions 90
Negative buck converter 91
Output divider 91
Duty cycle 91
Inductor 91
Output capacitor 92
Output filter 92
Input filter 93
Frequency compensation 93
Catch diode 93
Negative-to-positive buck-boost converter 93
Setting output voltage 94
Inductor 94
Output capacitor 95
Current steering diode 95
Positive buck converter 95
Duty cycle limitations 96
Inductor 97
Output voltage ripple 97
Output capacitor 97
Output filter 97
Flyback converter 98
Output divider 99
Frequency compensation 99
Snubber design 99
Output diode (D1) 100
Output capacitor (C1) 101
Totally isolated converter 102
Output capacitors 104
Load and line regulation 104
Frequency compensation 105
Positive current-boosted buck converter 105
Negative current-boosted buck converter 106
Negative input/negative output flyback converter 107
Positive-to-negative flyback converter 107
Voltage-boosted boost converter 108
Negative boost converter 109
Positive-to-negative buck boost converter 109
Current-boosted boost converter 109
Forward converter 110
Frequency compensation 112
Check margins 114
Eliminating start-up overshoot 114
External current limiting 114
Driving external transistors 116
Output rectifying diode 117
Input filters 119
Efficiency calculations 120
LT1070 operating current 120
LT1070 switch losses 121
Output diode losses 121
Inductor and transformer losses 121
Snubber losses 121
Total losses 121
Output filters 121
Input and output capacitors 123
Inductor and transformer basics 123
Cores with gaps 124
Inductor selection process 125
Transformer design example 127
Heat sinking information 130
Troubleshooting hints 130
Warning 130
Subharmonic oscillations 131
Inductor/transformer manufacturers 139
Core manufacturers 139
Bibliography 139
6 -Switching regulators for poets 141
Basic flyback regulator 142
-48V to 5V telecom flyback regulator 143
Fully-isolated telecom flyback regulator 144
100W off-line switching regulator 146
Switch-controlled motor speed controller 149
Switch-controlled peltier reference 149
Acknowledgments 150
7 -Step-down switching regulators 159
Basic step down circuit 159
Practical step-down switching regulator 159
Dual output step-down regulator 161
Negative output regulators 161
Current-boosted step-down regulator 162
Post regulation-fixed case 163
Post regulation-variable case 163
Low quiescent current regulators 163
Wide range, high power, high voltage regulator 167
Regulated sinewave output DC/AC converter 170
References 173
Appendix A 
173 
Appendix BGeneral considerations for switchingregulator design 175
Inductor selection 176
8 -A monolithic switching regulator with output noise 186
Introduction 186
Switching regulator "noise" 186
A noiseless switching regulator approach 187
A practical, low noise monolithic regulator 187
Measuring output noise 188
System-based noise "measurement" 191
Transition rate effects on noise and efficiency 191
Negative output regulator 192
Floating output regulator 192
Floating bipolar output converter 192
Battery-powered circuits 194
Performance augmentation 194
Low quiescent current regulator 194
High voltage input regulator 196
24V-to-5V low noise regulator 198
10W, 5V to 12V low noise regulator 199
7500V isolated low noise supply 200
References 202
Appendix AA history of low noise DC/DC 202
History 202
Measuring noise 206
Low frequency noise 206
Preamplifier and oscilloscope selection 206
Ground loops 209
Pickup 209
Poor probing technique 209
Violating coaxial signal transmission—felony case 210
Violating coaxial signal transmission— misdemeanor case 211
Proper coaxial connection path 211
Direct connection path 212
Test lead connections 212
Isolated trigger probe 213
Trigger probe amplifier 213
Breadboarding and Layout Considerations 217
5V to 12V Breadboard 218
5V to ± 15V breadboard 218
Demonstration board 218
Testing ripple rejection 220
Transformers 222
Inductors 222
Hints for lowest noise performance 223
Noise tweaking 223
Capacitors 224
Damper network 224
Measurement technique 224
Noise test data 224
Pot core 225
ER core 225
Toroid 227
E core 227
Summary 227
Conclusion 227
Rectifier reverse recovery 233
Ringing in clamp Zeners 238
Paralleled rectifiers 238
Paralleled snubber or damper caps 238
Ringing in transformer shield leads 238
Leakage inductance fields 239
External air gap fields 239
Poorly bypassed high speed logic 239
Probe use with a "LISN" 
239 
Conclusion 240
Summary 240
9 -Powering complex FPGA-based systems using highly integrated DC/DC Module regulator systems 242
Innovation in DC/DC design 242
DC/DC Module Regulators: Complete Systems in an LGA Package 242
48A from four parallel DC/DC Module regulators 244
Start-up, soft-start and current sharing 245
Conclusion 245
10 -Powering complex FPGA-based systems•using highly integrated DC/DCµ Module regulator systems 246
60W by paralleling four DC/DC µModule regulators 246
Thermal performance 246
Simple copy and paste layout 247
Conclusion 248
11 -Diode Turn-On Time Induced Failures in Switching Regulators 249
Introduction 249
Diode turn-on time perspectives 249
Detailed measurement scheme 249
Diode Testing and Interpreting Results 253
References 254
Section 3 -Linear Regulator Design 266
12 -Performance verification of low noise, low dropout regulators 267
Introduction 267
Noise and noise testing 267
Noise testing considerations 267
Instrumentation performance verification 267
Regulator noise measurement 269
Bypass capacitor (CBYP) influence 269
Interpreting comparative results 269
References 269
References 269
Appendix A 
276 
Noise minimization 276
Pass element considerations 276
Dynamic characteristics 277
Bypass capacitance and low noise performance 278
Output capacitance and transient response 278
Ceramic capacitors 278
AC voltmeter types 279
Rectify and average 279
Analog computation 279
Thermal 280
Performance comparison of noise driven AC voltmeters 280
Thermal voltmeter circuit 281
Section 4 -High Voltage and High Current Applications 284
13 -Parasitic capacitance effects in step-up transformer design 285
Brian Huffman 285
Appendix A 288
14 -High efficiency, high density, PolyPhase converters for high current applications 289
Introduction 289
How do PolyPhase techniques affect circuit performance? 289
Current-sharing 290
Output ripple current cancellation and reduced output ripple voltage 290
Improved load transient response 292
Input ripple current cancellation 293
Input ripple current cancellation 293
Design considerations 295
Selection of phase number 296
PolyPhase converters using the LTC1629 296
Layout considerations 296
Design example: 100A PolyPhase power supply 298
Design details 298
MOSFETs 298
Inductors 298
Capacitors 299
Test results 299
Summary 301
Section 5 -Powering Lasers and Illumination Devices 304
15 -Ultracompact LCD backlight inverters 305
Introduction 305
Limitations and problems of magnetic CCFL transformers 305
Piezoelectric transformers 305
Developing a PZT transformer control scheme 306
Additional considerations and benefits 310
Display parasitic capacitance and its effects 310
References 311
Appendix A Piezoelectric transformers 312
"Good Vibrations" 312
Piezowhat? 312
Alchemy and black magic 312
The fun part 313
A resonant personality 313
Piezoelectricity 314
Piezoelectric effect 314
Axis nomenclature 315
Electrical-mechanical analogies 315
Coupling 315
Electrical, mechanical property changes with load 315
Elasticity 316
Piezoelectric equation 316
Basic piezoelectric modes 316
Poling 316
Post Poling 317
Applied voltage 317
Applied force 317
Shear 317
Piezoelectric benders 317
Loss 318
Simplified Piezoelectric Element Equivalent Circuit 318
Simple stack piezoelectric transformer 318
Conclusion 322
16 -A thermoelectric cooler temperature•controller for fiber optic lasers 325
Introduction 325
Temperature Controller Requirements 325
Temperature Controller Details 326
Thermal Loop Considerations 326
Temperature Control Loop Optimization 327
Temperature Stability Verification 329
Reflected Noise Performance 332
References 334
17 -Current sources for fiber optic lasers 336
Introduction 336
Design criteria for fiber optic laser current sources 336
Detailed discussion of performance issues 336
Required power supply 336
Output current capability 336
Output voltage compliance 336
Efficiency 337
Laser connection 337
Output current programming 337
Stability 337
Noise 337
Transient response 337
Detailed discussion of laser protection issues 337
Overshoot 337
Enable 337
Output current clamp 337
Open laser protection 337
Basic current source 337
High efficiency basic current source 338
Grounded cathode current source 339
Single supply, grounded cathode current source 339
Fully protected, self-enabled, grounded cathode current source 340
2.5A, grounded cathode current source 342
0.001% noise, 2A, grounded cathode current source 344
0.0025% noise, 250mA, grounded anode current source 346
Low noise, fully floating output current source 346
Anode-at-supply current source 347
References 349
Appendix A 
349 
18 -Bias voltage and current sense circuits for avalanche photodiodes 355
Introduction 355
Simple current monitor circuits (with problems) 356
Carrier based current monitor 356
DC coupled current monitor 357
APD bias supply 358
APD bias supply and current monitor 359
Transformer based APD bias supply and current monitor 359
Inductor based APD bias supply 360
200µV output noise APD bias supply 362
Low noise APD bias supply and current monitor 363
0.02% accuracy current monitor 363
Digital output 0.09% accuracyµcurrent monitor 364
Digital output current monitor 364
Digital output current monitor and APD bias supply 367
Summary 367
References 370
Appendix A 
 
370 
Divider current error compensationlow—"side"shunt case 370
Divider current error compensation—"high side"shunt case 371
Ground loops 372
Pickup 372
Poor probing technique 372
Violating coaxial signal transmission—felony case 372
Violating coaxial signal transmission— misdemeanor case 373
Proper coaxial connection path 373
Direct connection path 373
Test lead connections 374
Isolated trigger probe 375
Trigger probe amplifier 375
Section 6 -Automotive and Industrial Power Design 384
19 -Developments in battery stack voltage measurement 385
The battery stack problem 385
Transformer based sampling voltmeter 386
Detailed circuit operation 386
Multi-cell version 388
Automatic control and calibration 388
Firmware description 392
Measurement details 392
Adding more channels 393
References 394
Part 
408 
Section 1 -Data Conversion 410
20 -Some techniques for direct digitization of transducer outputs 411
Jim Williams 411
21 -The care and feeding of high performance ADCs: get all the bits you paid for 423
Introduction 423
An ADC has many "inputs" 423
Ground planes and grounding 423
Supply bypassing 424
Reference bypassing 425
Driving the analog input 425
Switched capacitor inputs 425
Filtering wideband noise from the input signal 426
Choosing an op amp 426
Driving the convert-start input 426
Effects of jitter 427
Routing the data outputs 428
Conclusion 429
Family features 429
High speed A/D converters — world’s best power/speed ratio 423
22 -A standards lab grade 20-bit DAC with 0.1ppm/ºC drift 431
Introduction 431
20-bit DAC architecture 431
Circuitry details 433
Linearity considerations 433
DC performance characteristics 433
Dynamic performance 433
Conclusion 435
References 435
Appendix A 
 
435 
Approach and error considerations 437
Circuitry details 438
Construction 441
Results 441
Acknowledgments 441
23 -Delta sigma ADC bridge measurement techniques 478
Introduction 478
Low cost, precision altimeter uses direct digitization 479
How Many Bits? 479
Increasing Resolution with Amplifiers 479
How Much Gain? 481
ADC Response to Amplifier Noise 481
How Many Bits? 482
Faster or More Resolution with the LTC2440 483
How Many Bits? 484
Appendix A 
 
485 
RMS vs Peak-to-Peak Noise 486
Psychological Factors 486
24 -1ppm settling time measurement for a monolithic 18-bit DAC 497
Introduction 497
DAC settling time 497
Considerations for measuring DAC settling time 498
Sampling based high resolution DAC settling time measurement 499
Developing a sampling switch 500
Electronic switch equivalents 500
Transconductance amplifier based switch equivalent 500
DAC settling time measurement method 502
Detailed settling time circuitry 503
Settling time circuit performance 505
Using the sampling-based settling time circuit 505
References 507
Appendix A 
 
508 
Delay compensation 511
Circuit trimming procedure 511
Ohm's law 519
Shielding 520
Connections 521
Settling time circuit performance verification 524
Section 2 -Signal Conditioning 532
25 -Applications for a switched-capacitor instrumentation building block 535
Instrumentation amplifier 536
Ultrahigh performance instrumentation amplifier 536
Lock-in amplifier 537
Wide range, digitally controlled, variable gain amplifier 538
Precision, linearized platinum RTD signal conditioner 539
Relative humidity sensor signal conditioner 540
LVDT signal conditioner 541
Charge pump F.Vand V.F converters 542
12-bit A.D converter 543
Miscellaneous circuits 544
Voltage-controlled current source—grounded source and load 546
Current sensing in supply rails 547
0.01% analog multiplier 547
Inverting a reference 547
Low power, 5V driven, temperature compensated crystal oscillator 547
Simple thermometer 547
High current, "inductorless,"switching regulator 547
26 -Application considerations and circuits for a new chopper-stabilized op amp 549
Applications 553
Standard grade variable voltage reference 553
Ultra-precision instrumentation amplifier 553
High performance isolation amplifier 554
Stabilized, low input capacitance buffer (FET probe) 556
Chopper-stabilized comparator 557
Stabilized data converter 558
Wide range V.F converter 558
1Hz to 30MHz V.F converter 560
16-bit A/D converter 560
Simple remote thermometer 563
Output stages 563
References 566
27 -Designing linear circuits for 5V single supply operation 567
Linearized RTD signal conditioner 567
Linearized output methane detector 568
Cold junction compensated thermocouple signal conditioner 569
5V powered precision instrumentation amplifier 570
5V powered strain gauge signal conditioner 572
"Tachless"motor speed controller 572
4-20mA current loop transmitter 574
Fully isolated limit comparator 575
Fully isolated 10-bit A/D converter 576
28 -Application considerations for an instrumentation lowpass filter 580
Description 580
Tuning the LTC1062 580
LTC1062 clock requirements 581
Internal oscillator 582
Clock feedthrough 582
Single 5V supply operation 583
Dynamic range and signal/noise ratio 583
Step response and burst response 585
LTC1062 shows little aliasing 585
Cascading the LTC1062 585
Using the LTC1062 to create a notch 587
Comments on capacitor types 589
Clock circuits 589
Acknowledgement 590
29 -Micropower circuits for signal conditioning 591
Platinum RTD signal conditioner 591
Thermocouple signal conditioner 592
Sampled strain gauge signal conditioner 592
Strobed operation strain gauge bridge signal conditioner 594
Thermistor signal conditioner for current loop application 594
Microampere drain wall thermostat 595
Freezer alarm 596
12-Bit A/D converter 596
10-Bit, 100µA A/D converter 598
20µs sample-hold 599
10kHz voltage-to-frequency converter 600
1MHz voltage-to-frequency converter 602
Switching regulator 603
Post regulated micropower switching regulator 604
30 -Thermocouple measurement 613
Introduction 613
Thermocouples in perspective 613
Signal conditioning issues 615
Cold junction compensation 615
Amplifier selection 617
Additional circuit considerations 617
Differential thermocouple amplifiers 618
Isolated thermocouple amplifiers 618
Digital output thermocouple isolator 622
Linearization techniques 623
References 629
Appendix A 
 
629 
31 -Take the mystery out of the switched-capacitor filter 631
Introduction 631
Overview 631
The switched-capacitor filter 631
Circuit board layout considerations 632
Power supplies 634
Input considerations 635
Offset voltage nulling 635
Slew limiting 638
Aliasing 639
Filter response 640
What kind of filter do I use? Butterworth, Chebyshev, Bessel or Elliptic 640
Filter sensitivity 644
How stable is my filter? 644
Output considerations 645
THD and dynamic range 645
THD in active RC filters 645
Noise in switched-capacitor filters 645
Bandpass filters and noise—an illustration 647
Clock circuitry 647
Jitter 647
Clock synchronization with A/D sample clock 649
Clock feedthru 649
Conclusions 650
Bibliography 654
32 -Bridge circuits 655
Resistance bridges 655
Bridge output amplifiers 655
DC bridge circuit applications 656
Common mode suppression techniques 656
Single supply common mode suppression circuits 659
Switched-capacitor based instrumentation amplifiers 662
Optically coupled switched-capacitor instrumentation amplifier 663
Platinum RTD resistance bridge circuits 664
Digitally corrected platinum resistance bridge 665
Thermistor bridge 670
Low power bridge circuits 670
Strobed power bridge drive 672
Sampled output bridge signal conditioner 672
Continuous output sampled bridge signal conditioner 673
High resolution continuous output sampled bridge signal conditioner 674
AC driven bridge/synchronous demodulator 676
AC driven bridge for level transduction 676
Time domain bridge 677
Bridge oscillator—square wave output 678
Quartz stabilized bridge oscillator 679
Sine wave output quartz stabilized bridge oscillator 679
Wien bridge-based oscillators 680
Diode bridge-based 2.5MHz precision rectifier/AC voltmeter 683
References 686
33 -High speed amplifier techniques 696
Preface 696
Introduction 697
Perspectives on high speed design 697
Mr. Murphy's gallery of high speed amplifier problems 697
Tutorial Section 705
About Cables, Connectors and Terminations 706
About Probes and Probing Techniques 707
About Oscilloscopes 710
About Ground Planes 714
About Bypass Capacitors 715
Breadboarding Techniques 715
Oscillation 718
Applications Section I—Amplifiers 655
Fast 12-bit digital-to-analog converter (DAC) amplifier 720
2-Channel Video Amplifier 721
Simple Video Amplifier 721
Loop Through Cable Receivers 721
DC stabilization & mdash
DC stabilization & mdash
DC stabilization & mdash
DC stabilization & mdash
DC stabilization & mdash
High Speed Differential Line Receiver 725
Transformer Coupled Amplifier 726
Differential Comparator Amplifier with Adjustable Offset 727
Differential Comparator Amplifier with Settable Automatic Limiting and Offset 728
Photodiode Amplifier 729
Fast Photo Integrator 730
Fiber Optic Receiver 731
40MHz fiber optic receiver with adaptive trigger 731
50MHz high accuracy analog multiplier 731
Power Booster Stage 732
High Power Booster Stage 734
Ceramic Bandpass Filters 735
Crystal Filter 736
Applications Section II —Oscillators 736
Sine Wave Output Quartz Stabilized Oscillator 736
Sine Wave Output Quartz Stabilized Oscillator with Electronic Gain Control 736
DC Tuned 1MHz-10MHz Wien Bridge Oscillator 737
Complete AM radio station 738
Applications section III—Data conversion 739
1Hz–1MHz voltage-controlled sine wave oscillator 739
1Hz& ndash
8-bit, 100ns sample-hold 743
15ns current summing comparator 744
50MHz adaptive threshold trigger circuit 744
Fast Time-to-Height (Pulsewidth-to-Voltage) Converter 745
True RMS wideband voltmeter 747
Applications Section Iv —Miscellaneous Circuits 
749 
RF Leveling Loop 749
Voltage Controlled Current Source 750
High Power Voltage Controlled Current Source 750
18ns circuit breaker 751
References 752
Appendix A 
753 
ABC's of probes —Tektronix, Inc 753
The vital link in your measurement system 753
Why not use a piece of wire? 753
Benefits of using probes 755
How probes affect your measurements 755
Scope Bandwidth at the Probe Tip? 760
How ground leads affect measurements 761
How probe design affects your measurements 762
Tips on using probes 763
Introduction: 764
Measuring Amplifier Settling Time 771
The Oscillation Problem — Frequency Compensation Without Tears 775
Measuring Probe-Oscilloscope Response 781
An Ultra-Fast High Impedance Probe 783
Additional Comments on Breadboarding 785
FCC licensing and construction permit applications for commerical AM broadcasting stations 811
About Current Feedback 812
Current Feedback Basics 812
High Frequency Amplifier Evaluation Board 814
The contributions of Edsel Murphy to the understanding of the behavior of inanimate objects 816
I. Introduction 817
II. General Engineering 817
III. Mathematics 817
IV. Prototyping and Production 817
V. Specifying 818
References* 818
34 -A seven-nanosecond comparator for single supply operation 819
Introduction 819
The LT1394 —an overview 820
The rogue's gallery of high speed comparator problems 821
Tutorial section 824
About pulse generators 824
About cables, connectors and terminations 824
About probes and probing techniques 825
About oscilloscopes 829
About ground planes 832
About bypass capacitors 833
Breadboarding techniques 834
Applications 835
Crystal oscillators 835
Switchable output crystal oscillator 836
Temperature-compensated crystal oscillator (TXCO) 836
Voltage-controlled crystal oscillator (VCXO) 837
Voltage-tunable clock skew generator 838
Simple 10MHz voltage-to-frequency converter 839
Precision 1Hz to 10MHz voltage-to-frequency converter 840
Fast, high impedance, variable threshold trigger 842
High speed adaptive trigger circuit 842
18ns, 500µV sensitivity comparator 843
Voltage-controlled delay 844
10ns sample-and-hold 845
Programmable, sub-nanosecond delayed pulse generator 846
Fast pulse stretcher 848
20ns response overvoltage protection circuit 849
References 851
Appendix A 
851 
35 -Understanding and applying voltage references 856
Essential features 858
Reference pitfalls 859
Current-hungry loads 859
"NC" pins 860
Board leakage 860
Trim-induced temperature drift 860
Burn-in 861
Board stress 861
Temperature-induced noise 862
Reference applications 863
Conclusion 864
For further reading 864
Appendix A Buried Zener: low longterm driftand noise 864
36 -Instrumentation applications for a monolithic oscillator 867
Introduction 867
Clock types 867
A (very) simple, high performance oscillator 868
Platinum RTD digitizer 868
Thermistor-to-frequency converter 869
Isolated, 3500V breakdown, thermistor-to-frequency converter 870
Relative humidity sensor digitizer-hetrodyne based 871
Relative humidity sensor digitizer—charge pump based 872
Relative humidity sensor digitizer—time domain bridge based 873
40nV noise, 0.05µV/ºC drift, chopped bipolar amplifier 873
45nV noise, 0.05µV/ºC drift, chopped FET amplifier 875
Clock tunable, filter based sine wave generator 877
Clock tunable, memory based sine wave generator 877
Clock tunable notch filter 879
Clock tunable interval generator with 20 x 106:1 dynamic range 880
8-bit, 80µs, passive input, A/D converter 881
References 882
37 -Slew rate verification for wideband amplifiers 885
Introduction 885
Amplifier dynamic response 885
LT1818 Short form specifications 886
Pulse generator rise time effects on measurement 886
Subnanosecond rise time pulse generators 887
360ps rise time pulse generator 887
Circuit optimization 888
Refining slew rate measurement 890
References 892
Appendix A 
 
892 
38 -Instrumentation circuitry using RMS-to-DC converters 896
Introduction 896
Isolated power line monitor 896
Fully isolated 2500V breakdown, wideband RMS-to-DC converter 898
Low distortion AC line RMS voltage regulator 899
X1000 DC stabilized millivolt preamplifier 901
Wideband decade ranged x 1000 preamplifier 901
Wideband, isolated, quartz crystal RMS current measurement 902
AC voltage standard with stable frequency and low distortion 904
RMS leveled output random noise generator 905
RMS amplitude stabilized level controller 906
References 908
Appendix A 
 
908 
39 -775 nanovolt noise measurement for a low noise voltage reference 913
Introduction 913
Noise measurement 913
Noise measurement circuit performance 914
References 917
Appendix A 
918 
Appendix BInput capacitor selection procedure 918
Appendix CPower, grounding and shieldingconsiderations 919
Section 3 -High Frequency/RF Design 922
40 -LT5528 WCDMA ACPR, AltCPR and noise measurements 923
Introduction 923
41 -Measuring phase and delay errors accurately in I/Q modulators 927
Introduction 927
Measurements 929
First measurement—null out the I/Q modulator image signal with normal signal connections (Figure 41.6) 929
Second measurement—null out the I/Q modulator image signal with reversed differential baseband signals to the modulator's differential I-channel inputs (Figure 41.7) 930
Third measurement—null out the I/Q modulator image signal after reversing the I and Q inputs to the modulator (Figure 41.8) 930
Calculation of phase impairments 931
Applying the method 932
Conclusion 932
Subject Index 934