EP2S130F1020I4 Datasheet, PDF (737/768 Pages) List of Unclassifed Manufacturers – Stratix II Device Handbook, Volume 1

11. High-Speed Board Layout
Guidelines
SII52012-1.4
Introduction
PCB Material
Selection
Printed circuit board (PCB) layout becomes more complex as device pin
density and system frequency increase. A successful high-speed board
must effectively integrate devices and other elements while avoiding
signal transmission problems associated with high-speed I/O standards.
Because Altera^® devices include a variety of high-speed features,
including fast I/O pins and edge rates less than one hundred
picoseconds, it is imperative that an effective design successfully:
■ Reduces system noise by filtering and evenly distributing power to
all devices
■ Matches impedance and terminates the signal line to diminish signal
reflection
■ Minimizes crosstalk between parallel traces
■ Reduces the effects of ground bounce
This chapter provides guidelines for effective high-speed board design
using Altera devices and discusses the following issues:
■ PCB material selection
■ Transmission line layouts
■ Routing schemes for minimizing crosstalk and maintaining signal
integrity
■ Termination schemes
■ Simultaneous switching noise (SSN)
■ Electromagnetic interference (EMI)
■ Additional FPGA-specific board design/signal integrity information
Fast edge rates contribute to noise and crosstalk, depending on the PCB
dielectric construction material. Dielectric material can be assigned a
dielectric constant (_r) that is related to the force of attraction between
two opposite charges separated by a distance in a uniform medium as
follows:
F=
Q1Q2
4πεr2
Altera Corporation
May 2007
11–1