Sub strate Noise Coup ling in An a log/RF Circuits For a list ing of re cent ti tles in the Artech House Mic row ave Lib rary, turn to the back of this book. Sub strate Noise Coup ling in An a log/RF Cir cuits Stephane Bronckers Geert Van der Plas Gerd Vandersteen Yves Rolain artechhouse.com Li brary of Con gress Cataloging- in- Publication Data A cata log reco rd for this book is avail able from the U.S. Lib rary of Con gress. Brit ish Li brary Cat a logu ing in Pub li ca tion Data A cata logue rec ord for this book is avail able from the Briti sh Li brary. ISBN-13 978-1-59693-271-5 Cover de sign by Igor Valdman © 2010 ARTECH HOUSE 685 Can ton Street Norwood, MA 02062 All rights res erved. Printed and bound in the United States of Amer ica. No part of this book may be rep ro duced or util ized in any form or by any means, elect ronic or mechanical, in cludi ng pho - to copy ing, re cord ing, or by any in for ma tion stor age and retrieval sys tem, with out per mis sion in writ ing from the publ isher. All terms men tioned in this book that are known to be tradem arks or serv ice marks have been app ro pri ately cap i tal ized. Artech House can not at test to the acc u racy of this in form a tion. Use of a term in this book should not be reg arded as aff ecti ng the va lid ity of any tradem ark or serv ice mark. 10 9 8 7 6 5 4 3 2 1 ToKarenandmyfamily fortheirlove,trust, andconstantsupport Contents Foreword xiii Preface xv Acknowledgments xvii Chapter1 Introduction 1 1.1 IntroductionandMotivation 1 1.2 Bookoverview 4 References 5 Chapter2 SubstrateNoisePropagation 7 2.1 Introduction 7 2.2 ModelingtheSubstrate 8 2.2.1 AnalyticalResistanceCalculationBetween TwoContacts 9 2.2.2 FiniteDifferenceMethod 13 2.2.3 FiniteElementMethod 17 2.3 TheSubstrateModeledwithFDM 19 2.3.1 ExperimentalDescription 19 2.3.2 AnalysisoftheSubstrateNoisePropagation 20 2.3.3 Conclusions 27 2.4 TheSubstrateasaFiniteElementModel 28 2.4.1 SimulationMethodology 28 2.4.2 DealingwithN-DopedRegions 30 vii viii SubstrateNoiseCouplinginAnalog/RFCircuits 2.4.3 SimulationSetupfortheTestStructure 33 2.4.4 Comparison 33 2.4.5 Conclusions 33 2.5 Conclusions 34 References 36 Chapter3 PassiveIsolationStructures 39 3.1 Introduction 39 3.2 OverviewandDescriptionoftheDifferentTypesofPassive IsolationStructures 40 3.2.1 TheTemplateLayout 42 3.2.2 IntegratingtheDifferentTypesofGuardRings 43 3.2.3 SimulationSetup 44 3.3 PredictionandUnderstandingofGuardRings 44 3.3.1 ReferenceStructure 45 3.3.2 P-WellBlockIsolation 47 3.3.3 N-WellIsolation 50 3.3.4 P+ GuardRingShielding 52 3.3.5 TripleWellShielding 56 3.3.6 ComparisonandConclusion 60 3.4 DesignofanEffcientP+GuardRing 65 3.4.1 ImpedanceoftheGroundInterconnect 65 3.4.2 WidthoftheP+GuardRing 67 3.4.3 DistancetotheVictim 70 3.4.4 GuidelinesforGoodP+ GuardRingDesign 75 3.5 Conclusions 76 References 77 Chapter4 NoiseCouplinginActiveDevices 79 4.1 Introduction 79 4.2 SubstrateNoiseImpactonAnalogDesign 80 4.3 ImpactSimulationMethodology 82 4.3.1 EMSimulation 83 4.3.2 CircuitSimulation 86 4.4 TransistorTestBench 86 4.4.1 DescriptionoftheTransistorUnderTest 87 4.4.2 ModelingtheTransistorTestBench 87 4.4.3 ExperimentalValidation 92 4.5 SubstrateNoiseCouplingMechanismsinaTransistor 92 Contents ix 4.5.1 AnalyzingtheDifferentCouplingMechanisms inaTransistor 94 4.5.2 DescriptionandMeasurementoftheDeviceUnder Test 97 4.5.3 ModelingDifferentSubstrateNoiseCoupling Mechanisms 100 4.5.4 QuantifyingtheDifferentSubstrateNoiseCoupling Mechanisms 104 4.5.5 ExperimentalValidationoftheSubstrateNoise CouplingMechanisms 106 4.6 Conclusions 108 References 109 Chapter5 MeasuringtheCouplingMechanismsinAnalog/RFCircuits 111 5.1 Introduction 111 5.2 Measurement-BasedIdentifcationoftheDominant SubstrateNoiseCouplingMechanisms 114 5.2.1 MeasurementoftheDifferentSpurs 115 5.2.2 SensitivityFunctions 116 5.2.3 DeterminingtheInfuenceofthePCB 118 5.3 Example:900MHzLC-VCO 119 5.3.1 DescriptionoftheLC-VCO 119 5.3.2 SubstrateSensitivityMeasurements 120 5.3.3 RevealingtheDominantCouplingMechanism forFMSpurs 123 5.3.4 RevealingtheDominantCouplingMechanism forAMSpurs 128 5.3.5 InfuenceofthePCBDecouplingCapacitors ontheSubstrateNoiseImpact 130 5.3.6 Conclusions 132 5.4 StudyoftheCouplingMechanismsBetweenaPower AmpliferandanLC-VCO 133 5.4.1 DescriptionoftheDesignofthePPAand theLC-VCO 135 5.4.2 CouplingMechanismsBetweenthePPAand theLC-VCO 137 5.4.3 MeasuringtheDominantCouplingMechanisms 142 5.4.4 Conclusions 146