Altera Corporation 1
AN-448-1.3
Application Note 448
Stratix III P o wer Management
Design Guide
Introduction
This document provides recommendations and guidel ines for power
management system design in systems featu ring Altera Stratix
®
III
FPGAs. To help you design a proper power solution for yo ur system, this
document focuses on the areas and design flow shown in Figure 1.
Figure 1. Power Management Design Flow
There are many application-specific aspects to consider when powering
digital ICs, such as DC tolerance, system sequencing, and transient
requirements. In addition, other conc erns such as system cost, PCB real
estate, and efficiency play a crucial role in defining the final power
solution.
This design ex ample sequences through the design flow, as shown in
Figure 1. For this design example, an analog to digital converter (A D C )
and Memory IC will be integrated with a Stratix III device, as shown in
Figure 2. Note that this is not a reference design and the f inal sol u tion
only exhibits one of the many possible power solutions for the
application.
Cost, Size, and Efficiency Tradeoffs
Determining Power Management Specifications for Selected ICs
Choosing a Power Distribution Architecture
Creating a Power Budget Spreadsheet
Complying with Thermal and Signal Integrity Requirements
Defining PCB Layout and Voltage Regulator Selection
May 2007, Version 1.3
2 Altera Corporation
Stratix III Power Management Design Guide
Figure 2. Selected ICs
Cost, Size, and
Efficiency
Trade-offs
After designing an architecture for the basic blocks of your system, the
first step you should take in designing your power solution is to define
your PCB dimensions. The key considerations for your power solution
should include:
■ Cost
■ Size or real estate
■ Efficiency
Different end markets place varying weights on these solutions, which
makes it impossible to hav e a single solution that fit s all needs. You must
evaluate each of these fact ors carefully at the start of your design to create
the right power solution for your specific system.
Cost and Real Estate
The importance of cost and real estate varies within different market
segments. One market segment may value cost over real estate, or vice
versa, for their system, while another may value cost and real estate as
equals. For example, most medi cal markets favor real estate savings over
cost, while wireless markets favor cost over real estate. Most server and
computer markets value the two equally.
Stratix III
Memory ADC