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HIGH
FREQUENCY & HIGH SPEED
DIGITAL DESIGN: SIGNAL AND FUNCTIONAL PARTITIONING,
INTEGRATION & COMMON-MODE ARCHITECTURAL DERIVATION |
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The
concepts of: controlling signal integrity; improving
signal-to-noise ratios; minimizing development
of common-mode potentials; controlling - confining
unintended common-mode fields and effects into
defined regions for efficient functional partitioning
and systems-product integration for all high
frequency – high speed digital designs;
(including analogue-digital separations) may
all be categorized as subsets of the first axiom
of Electromagnetic Compatibility: THE SYSTEM-PRODUCT
DESIGN MUST BE FUNCTIONALLY COMPATIBLE WITHIN
ITSELF! This intra-system product compatibility
is inclusive of signal and product performance
to functional definitions, requirements and
specifications. The derivation of a common-mode
architectural design from the system-product
electrical architecture is essential to efficiently
implement functional (electromagnetic) compatibility
within a systems-product. |
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THREE
DAY COURSE OUTLINE |
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DAY ONE — |
Session
1.1 - Introduction to: common-mode effects;
field coupling transfers; common-mode architecture;
and, Electromagnetic Compatibility:
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Blocked and Lumped Equivalent Model, Simplified,
Descriptions
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Coupling Interrelationships to Chassis Structure
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Interface Connections as Antenna Equivalents
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Overview of Conductive-Case Shielding Containment
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Initial Susceptibility “Intrusions”
Presented by ESD, representing common-mode
effects
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Interface Role as “Exit and Entry Currents”
in Susceptibility – Immunity Performance
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Overview of common-mode and EMC Architectural
Considerations.
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Session
1.2 – Logic Devices and Circuit Boards:
Causal Relationships of Common-mode Fields and
Potentials from circuit devices
- Logic
Drivers and Cross-Conduction Currents
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Spectral Propagation Characteristics of Various
Waveforms
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Spread Spectrum Approaches to Distribute Spectral
Occupancy
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Common-mode Structures Within Circuit Boards
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Significance of Propagation Through an Imperfect
Plane – Inductive Formations
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Peak Currents and Repetitive Impulse Surges
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Coupling of Common-mode Potentials to Heat
Sinks and Heat Sink Arrays
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Storage Capacitors: Layout Locations, Methods,
Rationale and Resonances
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“Array” Effect of Multiple Circuit
Devices
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Interface Wires and Cables as Antenna Structures
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Session
1.3 – Field Transfers To Structures from
Circuit Boards: Common-mode Current Circulations
and Coupled Effects
- Concept
of Distributed Common-mode Transmission Lines
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Relationship and Modes of Field Transfers
to Chassis Planes (Mechanical Structures)
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Chassis Planes as Common-mode Image Returns
in Distributed Line and Surface Patch Modes
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Spectral Profile Alterations Derived from
Imposition of Chassis Planes
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Common-mode Field Potential Displacements
and Transfer Impedances to Chassis Structures
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Multi-Mode Propagation Arrays
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Equivalent “Antenna Radial Propagation”
of Common-mode Currents in Interface Wires
and Cables
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Beneficial Use of “Ground Nulls”
to Establish Controlled Reflections Within
Distributed Common-mode Field Displacements
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Susceptibility Effects with “Ground
Null” Implementations
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Intervals of “Ground Nulls”
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Concepts of Partitioning Through “Moats”
and “Isolation Zones”
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Session
1.4 – Circuit Board Layout Considerations:
Delineated for Signal Quality, Power Quality,
Common-mode Loss Reductions and Architectural
Controls
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Concept Review of Transmission Lines in Signal
and Power Distributions
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Flux Linkage and Inductance Cancellation
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Dichotomous “Breaks” in Transmission
Lines, and Occurrences of “Break-equivalents”
in Circuit Boards
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Descriptions of Return Images in Relationship
to Flux Linkage
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Reviews of Transmission Lines:
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Micro-Stripline
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Stripline
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Embedded Micro-Stripline
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Asymmetrical Stripline
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Edge-Coupled Differential Line
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Broadside Coupled Differential Line
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Transmission Line Impedance Characteristics
of Line Configurations Noted Above
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Flux Linkage Patterns and Rationale
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Power Plane Configurations and Impedances
with Signal Imaging
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Circuit Board “Stack-up” Considerations
for Power and Signal Distributions
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Power Planes and Edge Impedance Terminations
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Undercut Power Planes – Concept, Rationale
and Implementation
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Multiple Dielectric Separations
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Skin Effect and Skin Depths
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“3-W” and “10-W” Trace
Width Rules for Flux Boundaries of Traces
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Signal and Power Imaging for Various Board
Stack-ups Transmission Line Image Return Skew
with Layer-Jumping Through Vias
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Skew Route Patch for above
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Factors for Consideration of Imaging on Voltage
Planes
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Signal Impedance Matching
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Series and Parallel Signal Trace Terminations
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Circuit Board Functional (Common-mode and
EMC Architectural) “Partitioning”
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Blind and Buried Via Applications
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Faraday “Fences” Used for Partitioning
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“Picket Fences” Within Circuit
Boards for Board-Level Isolation Partitions
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3-Dimensional Partitions
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Analogue-Digital Partitioning
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Common-mode Inductor Techniques and Valuations
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Susceptibility / Immunity Partitioning in
Circuit Boards
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Derivative of Circuit Board Topologies and
EMC Architecture from Systems Electrical Architecture
– Preliminary Approach.
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DAY TWO — |
Session
2.1 – Paralleled Common-mode Loss and
Field Transfer Relationships of “Stacked”
Circuit Boards
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Common-mode Developments and Coupling With
Interconnected Circuit Boards
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Common-mode and EMC Issues Using Interconnected
Circuit Boards With Interface Cable Configurations
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Common-mode Displacements of Paralleled and
Interconnected Circuit Boards With Interface
Cables
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Electromagnetic Field Transfers and Displacement
Interactions Of Paralleled Circuit Boards
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Field Interactions Between Paralleled Boards
and Chassis Structures
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Ground “Null” Applications to
Paralleled Circuit Boards to Develop Signal
/ Noise Partitions
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Topology and Partitioning of Paralleled Circuit
Boards
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Backbone Implementation for Partitioning Between
Paralleled Circuit Boards.
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Session
2.2 – Perpendicular Bus-Structure Circuit
Boards with Motherboards: Common-mode Architectural
Descriptions
- Common-mode
Essentials of Perpendicularly – Connected
Circuit Boards
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Common-mode Architectural Considerations With
Perpendicular Circuit Boards
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Common-mode Field Distributed Transfer Interactions
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Field Displacements to Chassis Planes - Structures
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Common-mode Transfers In Architectural Paths
to Interface Cables
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Field Transfer Interactions to Interface Cables
With Multiple Cards
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EMC Implications of Ancillary Connections
to Perpendicular Circuit Boards
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Ground Null Applications to Motherboards and
Perpendicular Interface Circuit Boards
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Topological Layout Implications of Common-mode
Fields
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Session
2.3 – Backplane and Midplane Products
Integrated with Individual and Multiple Card
Cages: Common-mode Architecture to Minimize
Intra-System Coupling
- Backplanes
Viewed Initially With A Single Interconnected
Systems Board
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“Lumped Effects” of Common-mode
Considerations
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Card Cage Impositions With Backplanes With
Interconnected Systems Board
- Field
and Current Transfers to Card Cages from Interconnected
Systems Boards with (and to) Backplanes
- Backplane
Architecture to Systems Boards
- Preliminary
Common-mode Architectural and EMC Implications
of Interface Connections
- Susceptibility
/ Immunity Implications of Interface Common-Mode
Architecture
- Conceptual
Approach of Midplane Integration
- Common-mode
Aspect Ratios of System Boards
- Interface
Cable Connections to Backplanes and Systems
Boards
- Interconnections
of Multiple Systems Boards
- Approximation
of Antenna Structures Referenced to Chassis
(Card Cage) Planes
- Common-mode
References of Backplanes With Systems Boards
- Common-mode
Current Circulation Closure
- Special
Situation: Chassis Connection References for
DC Chassis-Isolated Backplanes
- Reference
Technique With Chassis Stripes and Via Patterns
- Establishment
of “Null Zones” in Backplanes
- Null
Zones and Regional Partitions
- Inter-layer
Backplane Referencing Method With Connection
Detail
- Backplane
Layering Construction, Stack-up Considerations
- Distributed
DC Power Sub-System Integration through Backplane
to Systems Boards
- System
Board Topology for Distributed DC Power Subsystem
- Interconnected
Systems-Card Edge Reference Application
- Card
Guide Connection Null Approach
- Null
Partition References of Interconnected Systems
Boards
- Derivation
of Common-mode EMC Architecture from Systems
Electrical Architecture
- Null
Partition References – Card Cage and
Backplane Integration
- Termination
of Null Partitions to Backplane
- Mid-Planes
- Partition Integration
- Mid-Plane
Partitions and Stack-up Concepts
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Mid-Plane Common-Mode Architectural Derivation
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Session
2.4 – EMC Implications of Systems Interconnections
- Initial
Implications Related to Systems Interconnections
- EMC
Issues Affecting Radiated Field Susceptibility
and Emissions
- Interrelationships
of Currents Between Systems Units
- Spatial
EMC Excitations Among Systems Unit Members
- Rack-Mount
EMC Integration of Multiple Card Cage Products
- Multiple
Card Cage Products – Independently and
Remotely Mounted
- Common-mode
EMC Excitations Imposed to Mechanical Mounting
Structures
- Field
Transfers (Interactions) Between Multiple
Card Cage System Products
- Lumped
Representations of Multiple Card Cage Products
- Rack-mount
Integration of Multiple Card Cage Products
- EMC
Mitigation Methods for Rack Mount Products
- Distributed
Common-mode Attenuation Technique Through
Interface Cables
- Implications
of Primary (Utility) Power Interconnections
- Interconnections
to Facility Power Distributions
- Historical
Implications of Facility Common-mode Events
- Voltage
and Current Ground Shifts From Facility Power
That Impact Systems’ Architecture
- Alternate
Architectural Systems Structure to Mitigate
Facility Common-mode Events
- Concept
of Software Coding and Physical Interface
Transport Communication Layers
- Essential
EMC Characteristics of Telecommunication Physical
Transport Layers
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Multi-wire Cables
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Twin-axial Cables
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Tri-axial Cables
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Session
2.5 - Immunity / Susceptibility Considerations
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Common-mode Entry and Exit Currents (to or
from systems-products)
- Null
Redistributions of Common-Mode Exit Currents
- Implications
of Redistributions to Shielded Cables
- Common-Mode
to Differential-Mode Conversions
- Common-Mode
Current Circulating in the Shield of the Cable
Wire Pairs
- EMC
Reference Interactions with Chassis-Case Structures
- Overview
of Case-Structure Apertures and Field Redistribution
- Transfer
Mechanisms of Susceptibility Response
- Effects
of Product Immersion into Radiated Field Excitation
Structures
- Concepts
of Bandwidth Limiting (Filtering / Conditioning)
- Single-ended
Signals, Conducted Series Common-mode Intrusions
and Superimposition
- Common-mode
and Differential-mode Approaches
- Concepts
of Demodulation and Detection of RF Carrier
Processes
- Electrostatic
Discharge (ESD) Processes and Impacts
- Fast
Transient (EFT) Coupled Impacts
-
Radiated Field Influences.
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DAY THREE — |
Session
3.1 – Product Shielding: Application of
Conceptual Theory
- Properties
of Electromagnetic Waves
- Concepts
of Electromagnetic Wave Impedance Mismatches
With Shields
- Transmission
Line Analogies of Shielding Processes
- Electromagnetic
Wave Impedances
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Near Field
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Transition Region
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Far Field
- Electromagnetic
Wave Impingement – Shield Performance
Mechanisms
- Reflection
Losses From Shield Surfaces
- Initial
Reflection Shielding Function of a Boundary
- Skin
Effect Boundaries
- Inter-boundary
Effects
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Thick Shields
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Thin Shields
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Surface Boundary Shields
- Shielding
Effectiveness Functions of a Continuous Shield
Boundary
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Reflection Losses
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Absorption Losses
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Compilations of Shielding Effectiveness Parameters
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Session
3.2 – Perimeter Case and Chassis Shielding:
Gaps, Seams, Slots, Perforations and Waveguides
Operating Below Cutoff
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Factors Limiting Shield Performance
- Coincidence
of Apertures to Circuits and Circuit Boards
- Applications
of Seams and Gaps as Shield Apertures
- Induction
Flux Equivalence in Shield Gap Formations
- Aperture-Arrayed
Shield Structures – Ventilation (Cooling)
Applications
- Waveguides
in Cutoff – Individual Apertures
- Waveguides
in Cutoff – Aperture Arrays
- Ventilation
Path – Plenum Shield Indirect Impingement
Concepts
- Cavity
Resonance in Enclosure Plenums
- Waveguides
in Cutoff – Performance Examples
- Perforated
Metals and Screen Shield Performance Examples
- Honeycomb
Shield Arrays
- Rectangular
and Circular Waveguides
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Induction Field External Coupling to Cables
from Apertures
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Session
3.3 - Shielded Modules Carried on Circuit Board
As Partitions
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Device-level Heat Sinks Utilized as Shields
- Completing
Shields of Device-level Heat Sinks
- Regional
Shield Partitions with Lumped Coupling Approximations
- Regional
Shield Partition – Topology Routing
Plans
- V-Plane
Partitioning in Regional Boundaries
- Inner-Board
Shielding Partitions with “Picket Fence”
Via Patterned Arrays
- Partition
Integration with “Shields” for
Externally-Removable Circuit Modules
- Partitions
Developed Within Boundaries of Removable Circuit
Modules
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Cavity Resonance Effects and “Q-Factor”
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Session
3.4 - Cable Shielding Applications
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Purpose of Cable Shielding
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Tri-axial Cable Shields
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Twin-axial Cable Shields
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Twisted Pairs
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Unshielded Twisted Pairs
- Cable
Shield Construction Details
- Cable
Shields as Boundary Partitions
- Common-mode
Cable “Image Return” Functions
of Chassis, Structures, and Earth
- Importance
of Connector Characteristics
- Shield
Categories of Multi-Conductor Shielded Cables
- Twisted
and Twisted-Shielded Pairs Within Multi-Conductor
Cables
- Significance
of Shield Termination Impedance
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Session
3.5 – Personnel Electrostatic Discharge:
History; Delineated ESD Wave-Shape Continuum
for Multiple Conditions as Found in Nature;
Comparisons of ESD Continuum to Requirements
of IEC Standards
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Delineated Descriptions of ESD Waveforms and
Implied Spectra Found “In Nature”
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Human “Finger-Tip” ESD Events
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ESD Event Waveforms From Personnel Through
Metallic Intervening Objects
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ESD Event Waveforms from Personnel Through
“Mobile Furnishings”
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ESD Mechanisms of Propagation to Systems-Products
Under Varied Installation Conditions
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ADDITIONAL - OPTIONAL - INSTRUCTION—
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Session
4.0 – Specific Design Reviews: Examination
of Specific Products in Comparison to the Examples
Provided in the Course.
- Additional
instruction may be provided as an extension
of the course by performing specific design
reviews on systems-product designs in conjunction
with the responsible development teams. This
option tends to improve the significance and
retention of the course instruction by applying
the examples directly to “real-hardware”.
The design reviews typically utilize comparative
examples extracted from the course material
in explanatory application to the results
of the systems-product design investigations
and reviews. The product examples selected
for design review are intended to be unique
and proprietary to the client contracting
for this course. Depending on the number of
products examples selected and the detail
of the review, additional time may be required
for the course schedule.
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