DC25_Paper_Track13_DifferentialSkewMitigationTechniqueResults_Kinney_V3.pdf

1、Information Classification:GeneralWelcome to ConferenceJanuary 2830,2025Santa Clara Convention Center1ExpoJanuary 2930,2025 Information Classification:GeneralDifferential Skew Mitigation Technique ResultsChris Kinney,(Google,Formerly Intel)Chris Kinney(Google),Vijay Kunda(Intel)Yi Amy H Luoh(Intel),

2、Xiaoning Ye(Intel)2Information Classification:GeneralImageSPEAKERChris KinneySignal Integrity Engineer,GChris Kinney is a signal integrity engineer for 18 years at Google,Intel,Micron and Kioxia.He is currently working on signal integrity challenges with Google Cloud hardware.He has patents and pape

3、rs on high-density interconnect technology and power delivery.Prior to Intel he designed microwave and millimeter wave circuits.He received his M.S.degree in electrical engineering from the University of California,Los Angeles.3Information Classification:General1.Differential Intra-Pair Skew2.PCB Ro

4、uting Skew Mitigation Techniques3.Glass Style4.Material Selection5.Test Method6.Differential Insertion Loss Measurements7.Differential Intrapair Skew MeasurementsOutline4Information Classification:GeneralUnit Intervals(UI)112 Gbps PAM4=17.85 ps(28 GHz Nyquist)PCIe Gen 7=15.625 ps(32 GHz Nyquist)Gene

5、ral rule-of-thumb Skew=10%UI Alternatively,differential-to-common mode conversion metric TX/RX PHY,package,connector,cable and PCB routing contribute to overall channel skew.Differential Intra-Pair Skew5Information Classification:GeneralPCB Routing Skew Mitigation Techniques6Mitigation TechniquePros

6、ConsSpread GlassBuilt into weaveAdditional material process(standard now)Glass Dk more closely matched to resin(E,K,K2)Built into weaveNew material qualification,cost and availabilityMixed weave typeBuilt into stack-upLimited selectionBoard RotationEasily implemented on current designsLow panel util