PDN Layout Requirements For PCB Designers and CAD Engineers

76 Pages·2013·4.034 MB·English

by  Qualcomm Technologies Inc.

PDN Layout
Requirements
For PCB Designers and CAD
Engineers
Qualcomm Technologies, Inc.
80-VT310-16 Rev. A
Confidential and Proprietary - Qualcomm Technologies, Inc.
Restricted Distribution: Not to be distributed to anyone who is not an employee of either Qualcomm or its
subsidiaries without the express approval of Qualcomm's Configuration Management.
Confidential and Proprietary - Qualcomm Technologies, Inc.

NO PUBLIC DISCLOSURE PERMITTED: Please report postings of this document on public servers or websites to: [email protected].

Restricted Distribution: Not to be distributed to anyone who is not an employee of either Qualcomm or its subsidiaries without the express approval of Qualcomm's
Configuration Management.

Not to be used, copied, reproduced, or modified in whole or in part, nor its contents revealed in any manner to others without the express written permission of Qualcomm
Technologies, Inc.

Qualcomm is a trademark of QUALCOMM Incorporated, registered in the United States and other countries. MSM is a trademark of QUALCOMM Incorporated, registered
in the United States and other countries. All QUALCOMM Incorporated trademarks are used with permission. Other product and brand names may be trademarks or
registered trademarks of their respective owners.

This technical data may be subject to U.S. and international export, re-export, or transfer (“export”) laws. Diversion contrary to U.S. and international law is strictly
prohibited.

Qualcomm Technologies, Inc.
5775 Morehouse Drive
San Diego, CA 92121
U.S.A.
© 2013 Qualcomm Technologies, Inc.
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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
Agenda
• What is a Power Distribution Network (PDN)?
• Why is the PDN Important?
• TO DO LIST
– How Best to Implement It
 PDN first
 Parallel loops
 Smaller loops, tighter loops
 Thermal considerations
• PDN Basics
– Theory Behind the “How“
 RLC and PDN Impedance Profile, |Z(f)|
• Q & A

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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
Related Documents
 80-VT310-13: Power Delivery Network Design
 80-VT310-15: PDN Capacitor Optimization Guidelines
 DP25-Nxxxx-1/2: Baseband IC Breakout Study (Nxxxx is
baseband IC family number)

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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
What is Power Distribution Network (PDN)?
PMIC
Load
Ref) http://science.howstuffworks.com/nuclear-power-pictures.htm
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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
What’s in the PCB PDN?
 The Switched Mode Power Supply (SMPS) or Low Dropout (LDO) regulator residing in
the Power Management IC (PMIC)
 PMIC Inductor + Bulk Capacitor(s)
 All passive components and their connections to the processor power grid
 Copper traces connecting the PMIC output to the processor power pins
 Copper plane connecting processor ground pins to PMIC ground pins

Bulk capacitors
MSM™
PMIC
Local decoupling
capacitors
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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
Why is PDN Important?
 A properly designed PDN helps ensure supply voltage
compliance to the required operating conditions of
processors and other integrated circuitry.

 Excessive PDN noise can result in circuit timing jitter,
over/under-shoot voltage, or EMI radiation that may result
in system instability.
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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
TO DO LIST
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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
1. PDN First
 Let’s think about the priorities in city plan
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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A
Plan & Route Power/Ground First!
BOM: IC devices, Output discrete devices,
Schematic
Decoupling Capacitors.
Assign power/ground plane layers first!
Stack-up
& close together!
Floorplan Place decoupling capacitors first!
Route to decoupling capacitors first!
Rev. Routing
Route critical power/ground nets first!
Meet
Follow Qualcomm PDN specs
Z ?
spec
Tape-out
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Confidential and Proprietary - Qualcomm Technologies, Inc. | MAY CONTAIN U.S. AND INTERNATIONAL EXPORT CONTROLLED INFORMATION | 80-VT310-16 Rev. A