Why Time Domain - CST Computer Simulation Technology · •May-06 Contents Power Plane Analysis TDR...

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Why Time Domain ?

JAY


Contents

Power Plane AnalysisTDR & EYE SimulationX-Talk for Stacked CSPX-Talk for BGALaser Via Transient AnalysisDifferential T-Line BehaviorUnwanted Behavior of FPCBHigh Speed Meander PatternT-Line Noise Behavior


Power Plane Analysis 1

E Probee1

e2

50x50mm1mm Thick

εr 3.8

Input Port

75600 / 75MB / 7M 1S

Am{S11}

S11 versusfrequency

Division

Interesting FrequencyBand (e.g. 1-6 GHz)

Input signalin time domain

FFT

transientsimulation

Reflected signalin time domain

FFT, ARF

Spectrum of reflected signal

Never miss a resonance !



e1 E-Probe

e2 E-Probe

Time Domain

Gaussian

Frequency Domain



Propagation AnalysisEigen ☞ PropagationSwitching BehaviorEM Spreading

Current Input

Charging Switching

1.38n 1.48n 1.58n

1.68n 1.78n 1.78n

32256 / 61MB / 1M 1S


TDR & EYE Simulation

Template Base PostprocessingTDR FunctionMode Selection

EYE Macro FunctionTransition & Bit

101840 / 90MB / 2M 58S

5.45GHz 6.45 GHz


X-Talk for Stacked CSP 1

High Frequency InductanceInductive Current by wire to wireIncreased by closer distance

Perspective View Top View

Front ViewSide View

8 Soldering Ball3 Wires / Ball24 Bonding Wires



Current ConcentrationAt via to pattern connection pointX-Talk Noise at neighbor patterns

3GHz 10GHz

VictimAggressor



Most X-Talk at Upper Wire15% of Output at 3GHz25% of Output at 10GHzValid Frequency = 3GHz

3GHz

10GHz

3GHz 10GHz

332112 Mesh / 126MB / 35M 12S332112 Mesh / 200MB / 1H 37M 52S

Upper Wire

Mid Wire

Lower Wire


X-Talk for BGA 1

Time Domain Analysis for BGAE-Field Probe

Excitation PortTerminations

895900 / 442MB / 1H 44M 58S


X-Talk for BGA 2

Surface Current SpreadingBy high speed transitionX-Talk, Unwanted RadiationMonitored by animated plot

3GHz X-Talk 10GHz X-Talk


Laser Via Transient Analysis 1

Complex Pattern of Laser ViaBy Laser on Buildup BoardCone Style & Land PatternNeed Efficient Mesh By FI-PBA

Port 1 Port 2Laser Via


Laser Via Transient Analysis 2

Transient MonitoringUnexpected EM PropagationMonitoring of Surface Current Distribution

40P 70P 100P

40P 50P 60P 70P

352800 / 250MB / 1H 29M 48S


Differential T-Line Behavior

Real EM PropagationCorner Reflection DifferenceCommon Mode Changing – EMI

200P 450P 600P

238000 / 126MB / 4M 45s


Unwanted Behavior of FPCB

X-Talk & Loss by InterferenceInsertion Loss : A < B < C < DX-Talk : A < B < D < C Issues After 10 GHzNeed Stripeline W/ Ground Plane

B. 90° BendingA. Flat

D. Outer FoldingC. Inner Folding

FLAT: 264784 / 140MB / 58M 10SBEND: 835744 / 300MB / 5H 33M 10SIFOLD: 264784 / 140MB / 58M 10SOFOLD: 1360800 / 560MB / 8H 42M 33S

Flat Bending

Inner FoldingOuter Folding

Inner Folding Outer Folding


High Speed Meander Pattern

Timing Control for Data Bus4 Turn Meander ProblemWeaken Signal at 6G, 12 GUnwanted Radiation at 12G

5mm32mm

10mm

2mm

Port 1

Port 2Port 4

Port 3

1Turn 6GHz

1Turn 12GHz

4Turn 6GHz

4Turn 12GHz4Turn S21

1615950 / 680MB / 1H 12M 50S

1Turn S43


T-Line Noise Behavior

Simultaneous Excitation2.5G, 3G, Noise SourceRadited Noise at H.F. 2.5GHz

3GHz

Noise Source

10GHz Noise 20GHz Noise

Output Signals Output Signals

336798 / 660MB / 4M 36S

2.5GHz Pulse

3GHz Pulse


Conclusions 1

Real X-Talk by Transient AnalysisCSP / BGA by Pulse Excitation

Transient Monitoring by Animated PlotUnwanted Radiation / Surface CurrentLaser Via Complex Pattern – FI-PBA

Mode Changing by ReflectionDifferential Mode to Common Mode – EMI

Interference and Radiation of FPCBX-Talk by High Speed Pulse Set Excitation


Conclusions 2

No More MeanderNo More Signal Propagation and Why & Where

Simultaneous SwitchingSignal Propagation with External Noise

TDR SimulationGet Easy Clue About Impedance Mismatching

Wave Propagation of Power Plane Eigen Mode for RadiationSignal Propagation Through Conductor Path

Why Time Domain - CST Computer Simulation Technology · •May-06 Contents Power Plane Analysis TDR...

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