Pcb Level Power Integrity Design From Pre-Layout To Post Route.pdf

PCB level power integrity
design from pre-layout to post
route.
Chihong Ding; Bob Evans; Quinn Gaumer; Niliels
Jensen ; Subramanian Ramanathan; Goutham
Sabavat; Stephen Scearce; Doug White
Presented by Stephen Scearce
Manager Cisco Systems
High-Speed Design Group
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 1
Agenda

PI Fundamentals (What is it and Why do we care. )

Pre Route IR Analysis

Post Route IR Verification

Pre Route AC Analysis

Post Route AC Verification
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 2
PI is essential to system operation

EMC Noise

Physical Reliability of our PCB

Bit Error Rate for serial links

RtReturn C urren tCt Cross tlktalk

Device Timing Reduction

…..
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 3
Why is PI important?
Setup/Hold Margin Reduction
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 4
Simultaneous Switching Noise (SSN)

Noise caused by several drivers switching at the same time
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 5
Simultaneous Switching Noise (SSN)
1 Bit 5 Bits
22 Bits

This is the noise generated when all the bit are running with
the same pattern

More bits switching - > Higher noise levels
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 6
SSN Eye Diagram: 22 Bit Switching
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 7
SSN Eye Diagram: 112 Bit Switching
Presentation_ID © 2006 Cisco Systems, Inc. All rights reserved. Cisco Confidential 8
What is Power Integrity?
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Power System Design
VRM
Bulk Caps Ceramic Package
Caps Caps
PCB Plane Die Cap
Cap
Presentation_ID © 2006 C