This document provides practical, common guidelines for incorporating PCI Express interconnect
layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10-
layer or more server baseboard designs. Guidelines and constraints in this document are intended
for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI
Express devices located on the same baseboard (chip-to-chip routing) and interconnects between
a PCI Express device located “down” on the baseboard and a device located “up” on an add-in
card attached through a connector.
This document is intended to cover all major components of the physical interconnect including
design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card
edge-finger and connector considerations. The intent of the guidelines and examples is to help
ensure that good high-speed signal design practices are used and that the timing/jitter and
loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect.
However, while general physical guidelines and suggestions are given, they may not necessarily
guarantee adequate PERFORMANCE of the interconnect for all layouts and implementations.
Therefore, designers should consider modeling and simulation of the interconnect in order to
ensure compliance to all applicable specifications.
The document is composed of two main sections. The first section provides an overview of
general topology and interconnect guidelines. The second section concentrates on physical layout
constraints where bulleted items at the beginning of a topic highlight important constraints, while
the narrative that follows offers additional insight.
Abstract: How smart is your LED lighting system? While LED lighting holds the promise of reducingenergy consumption and maintenance costs, smart LED lighting designs improve system PERFORMANCE in
We provide complete power solutions with a full lineup of power managementproducts. This brochure provides an overview of our high PERFORMANCE DC/DC switching regulatorcontrollers for applications including datacom, telecom, industrial, automotive, medical, avionicsand control systems. We make power design easier with our industry-leading field applicationengineering support; a broad selection of demonstration boards with schematics, layout filesand parts lists; SwitcherCAD® software for simulation, application notes and comprehensivetechnical documentation.
Linear Technology’s high PERFORMANCE battery management ICsenable long battery life and run time, while providing precision charging control, constantstatus monitoring and stringent battery protection. Our proprietary design techniques seamlesslymanage multiple input sources while providing small solution footprints, faster charging and100% standalone operation. Battery and circuit protection features enable improved thermalPERFORMANCE and high reliability operation.
Abstract: Nonideal cable dispersive effects can affect system PERFORMANCE. This application note discusses the twomain loss effects related to cables (skin-effect and dielectric losses), and presents a simple method of modeling thecable for use in standard SPICE simulators.
Abstract: Field-programmable gate arrays (FPGAs) are used in a wide variety of applications and end markets, including digital signalprocessing, medical imaging, and high-PERFORMANCE computing. This application note outlines the issues related to powering FPGAs.It also discusses Maxim's solutions for powering Altera® FPGAs.
While simplicity and high effi ciency (for cool running) areno longer optional features in isolated power supplies, itis traditionally diffi cult to achieve both. Achieving higheffi ciency often requires the use of advanced topologiesand home-brewed secondary synchronous rectifi cationschemes once reserved only for higher power applications.This only adds to the parts count and to the designcomplexity associated with the reference and optocouplercircuits typically used to maintain isolation. Fortunately, abreakthrough IC makes it possible to achieve both high efficiency and simplicity in a synchronous fl yback topology.The LT®3825 simplifi es and improves the PERFORMANCE oflow voltage, high current fl yback supplies by providingprecise synchronous rectifi er timing and eliminating theneed for optocoupler feedback while maintaining excellentregulation and superior loop response.
Advancements in board assembly, PCB layout anddigital IC integration have produced a new generationof densely populated, high PERFORMANCE systems. Theboard-mounted point-of-load (POL) DC/DC power suppliesin these systems are subject to the same demandingsize, high power and PERFORMANCE requirements asother subsystems. The rigorous new POL demands aredifficult to meet with traditional controller or regulatorICs, or power modules.
As the PERFORMANCE of many handheld devices approachesthat of laptop computers, design complexity also increases.Chief among them is thermal management—how doyou meet increasing PERFORMANCE demands while keepinga compact and small product cool in the user’s hand?For instance, as battery capacities inevitably increase,charge currents will also increase to maintain or improvetheir charge times. Traditional linear regulator-based batterychargers will not be able to meet the charge currentand effi ciency demands necessary to allow a product torun cool. What is needed is a switching-based chargerthat takes just about the same amount of space as a linearsolution—but without the heat.
Each year Vishay releases thousands of new components that enable our customers to create new and superior end products. We recognize that offering unique component solutions helps improve the PERFORMANCE of next-generation devices, overcome technical barriers, and create new markets.
