ATX Version 3.0 Multi Rail Desktop Platform Power Supply

Design Guide

ID Date Version Classification
336521 02/01/2023 Public

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Document Table of Contents
Document Table of Contents
Legal Revision History Introduction Processor Configurations PCI Express* Add-in Card Considerations Electrical Mechanical Acoustics Environmental Electromagnetic Compatibility Safety Reliability CFX12V Specific Guidelines 2.0 LFX12V Specific Guidelines 2.0 ATX12V Specific Guidelines 3.0 SFX12V Specific Guidelines 4.0 TFX12V Specific Guidelines 3.0 Flex ATX Specific Guidelines 2.0
Legal
Revision History
Introduction
Introduction Alternative Low Power Mode for Power Supplies Reference Documentation Terminology
Alternative Low Power Mode for Power Supplies
Reference Documentation
Terminology
Processor Configurations
Processor Configurations - RECOMMENDED High End Desktop Market Processor Considerations
Processor Configurations - RECOMMENDED
High End Desktop Market Processor Considerations
High End Desktop Market Processor Considerations Modular Power Supply Connectors Overclocking Recommendations
Modular Power Supply Connectors
Overclocking Recommendations
PCI Express* Add-in Card Considerations
PCI Express* Add-in Card Considerations PCIe* Add-in Card Power Excursions PCIe* AIC Auxiliary Power Connectors PCIe* Add-in Card Auxiliary Power Connectors Sideband Signals
PCIe* Add-in Card Power Excursions
PCIe* Add-in Card Power Excursions PCIe* Add-in Card and PSU Power Budgets PSU Power Excursion
PCIe* Add-in Card and PSU Power Budgets
PSU Power Excursion
PCIe* AIC Auxiliary Power Connectors
PCIe* Add-in Card Auxiliary Power Connectors Sideband Signals
PCIe* Add-in Card Auxiliary Power Connectors Sideband Signals Sense1 / Sense0 (Required) CARD_PWR_STABLE (Optional) CARD_CBL_PRES# (Optional) Sideband Signals DC Specifications (Required)
Sense1 / Sense0 (Required)
CARD_PWR_STABLE (Optional)
CARD_CBL_PRES# (Optional)
Sideband Signals DC Specifications (Required)
Electrical
Electrical AC Input - REQUIRED DC Output – REQUIRED Timing, Housekeeping and Control – REQUIRED Reset After Shutdown Output Protection
AC Input - REQUIRED
AC Input - REQUIRED Input Over Current Protection – REQUIRED Inrush Current – REQUIRED Input Under Voltage – REQUIRED
Input Over Current Protection – REQUIRED
Inrush Current – REQUIRED
Input Under Voltage – REQUIRED
DC Output – REQUIRED
DC Output – REQUIRED DC Voltage Regulation – REQUIRED DC Output Current – REQUIRED Remote Sensing - RECOMMENDED Other Low Power System Requirements Output Ripple Noise - REQUIRED Capacitive Load – RECOMMENDED Closed Loop Stability - REQUIRED +5V DC / +3.3V DC Power Sequencing - REQUIRED Voltage Hold-Up Time - REQUIRED 12V2 DC Minimum Loading - REQUIRED
DC Voltage Regulation – REQUIRED
DC Output Current – REQUIRED
Remote Sensing - RECOMMENDED
Other Low Power System Requirements
Output Ripple Noise - REQUIRED
Capacitive Load – RECOMMENDED
Closed Loop Stability - REQUIRED
+5V DC / +3.3V DC Power Sequencing - REQUIRED
Voltage Hold-Up Time - REQUIRED
12V2 DC Minimum Loading - REQUIRED
Timing, Housekeeping and Control – REQUIRED
Timing, Housekeeping and Control – REQUIRED PWR_OK – REQUIRED Power-Up Cross Loading Condition – REQUIRED PS_ON# – REQUIRED +5VSB – REQUIRED Power-On Time – REQUIRED Rise Time – REQUIRED Overshoot at Turn-On / Turn-Off – REQUIRED
PWR_OK – REQUIRED
Power-Up Cross Loading Condition – REQUIRED
PS_ON# – REQUIRED
+5VSB – REQUIRED
Power-On Time – REQUIRED
Rise Time – REQUIRED
Overshoot at Turn-On / Turn-Off – REQUIRED
Reset After Shutdown
Reset After Shutdown +5VSB at Power-Down – REQUIRED +5VSB Fall Time - RECOMMENDATION
+5VSB at Power-Down – REQUIRED
+5VSB Fall Time - RECOMMENDATION
Output Protection
Over Voltage Protection (OVP) – REQUIRED Short Circuit Protection (SCP) – REQUIRED No-Load Situation – REQUIRED Over Current Protection (OCP) – REQUIRED Over Temperature Protection (OTP) – REQUIRED Output Bypass – REQUIRED Separate Current Limit for 12V2 - OPTIONAL Overall Power Supply Efficiency Levels Power Supply Efficiency for Energy Regulations - ENERGY STAR* and CEC (California Energy Commission) PC Computers with High Expandability Score - RECOMMENDED
Over Voltage Protection (OVP) – REQUIRED
Short Circuit Protection (SCP) – REQUIRED
No-Load Situation – REQUIRED
Over Current Protection (OCP) – REQUIRED
Over Temperature Protection (OTP) – REQUIRED
Output Bypass – REQUIRED
Separate Current Limit for 12V2 - OPTIONAL
Overall Power Supply Efficiency Levels
Power Supply Efficiency for Energy Regulations - ENERGY STAR* and CEC (California Energy Commission) PC Computers with High Expandability Score - RECOMMENDED
Mechanical
Mechanical Labeling and Marking - RECOMMENDED Connectors - REQUIRED Airflow and Fans - RECOMMENDED
Labeling and Marking - RECOMMENDED
Connectors - REQUIRED
AC Connector DC Connectors
AC Connector
DC Connectors
DC Connectors Main Power Connector – REQUIRED Peripheral Connectors Floppy Drive Connector – Do Not Include (For Historical Reference Only) PCI-Express (PCIe*) Add-in Card Connectors (Recommended) +12 V Power Connector Serial ATA* Connectors – REQUIRED
Main Power Connector – REQUIRED
Peripheral Connectors
Floppy Drive Connector – Do Not Include (For Historical Reference Only)
PCI-Express (PCIe*) Add-in Card Connectors (Recommended)
+12 V Power Connector
Serial ATA* Connectors – REQUIRED
Airflow and Fans - RECOMMENDED
Airflow and Fans - RECOMMENDED Fan Location and Direction Fan Size and Speed Venting
Fan Location and Direction
Fan Size and Speed
Venting
Acoustics
Acoustics – RECOMMENDED
Acoustics – RECOMMENDED
Environmental
Environmental Temperature – RECOMMENDED Thermal Shock (Shipping) - RECOMMENDED Humidity – RECOMMENDED Altitude – RECOMMENDED Mechanical Shock – RECOMMENDED Random Vibration – RECOMMENDED
Temperature – RECOMMENDED
Thermal Shock (Shipping) - RECOMMENDED
Humidity – RECOMMENDED
Altitude – RECOMMENDED
Mechanical Shock – RECOMMENDED
Random Vibration – RECOMMENDED
Electromagnetic Compatibility
Electromagnetic Compatibility Emissions – REQUIRED Immunity - REQUIRED Input Line Current Harmonic Content - OPTIONAL Magnetic Leakage Field - REQUIRED Voltage Fluctuations and Flicker – REQUIRED
Emissions – REQUIRED
Immunity - REQUIRED
Input Line Current Harmonic Content - OPTIONAL
Magnetic Leakage Field - REQUIRED
Voltage Fluctuations and Flicker – REQUIRED
Safety
Safety North America – REQUIRED International – REQUIRED Proscribed Materials - REQUIRED Catastrophic Failure Protection - RECOMMENDED
North America – REQUIRED
International – REQUIRED
Proscribed Materials - REQUIRED
Catastrophic Failure Protection - RECOMMENDED
Reliability
Reliability - RECOMMENDED Reliability – PS_ON# toggle for S0ix mode - REQUIRED
Reliability - RECOMMENDED
Reliability – PS_ON# toggle for S0ix mode - REQUIRED
CFX12V Specific Guidelines 2.0
CFX12V Specific Guidelines 2.0 Physical Dimensions – REQUIRED
Physical Dimensions – REQUIRED
LFX12V Specific Guidelines 2.0
LFX12V Specific Guidelines 2.0 Physical Dimensions - REQUIRED
Physical Dimensions - REQUIRED
ATX12V Specific Guidelines 3.0
SFX12V Specific Guidelines 4.0
SFX12V Specific Guidelines 4.0 Lower Profile Package - Physical Dimensions - REQUIRED Fan Requirements - REQUIRED Top Fan Mount Package - Physical Dimensions -REQUIRED Fan Requirements - REQUIRED Reduced Depth Top Mount Fan - Physical Fan Requirements - REQUIRED Standard SFX Profile Package – Physical Dimensions - REQUIRED Fan Requirements - REQUIRED PS3 Form Factor-Physical Dimensions - REQUIRED Fan Requirements - REQUIRED
Lower Profile Package - Physical Dimensions - REQUIRED
Fan Requirements - REQUIRED
Top Fan Mount Package - Physical Dimensions -REQUIRED
Fan Requirements - REQUIRED
Reduced Depth Top Mount Fan - Physical
Fan Requirements - REQUIRED
Standard SFX Profile Package – Physical Dimensions - REQUIRED
Fan Requirements - REQUIRED
PS3 Form Factor-Physical Dimensions - REQUIRED
Fan Requirements - REQUIRED
TFX12V Specific Guidelines 3.0
TFX12V Specific Guidelines 3.0 Physical Dimensions - REQUIRED Mounting Options - RECOMMENDED Chassis Requirements - RECOMMENDED
Physical Dimensions - REQUIRED
Mounting Options - RECOMMENDED
Chassis Requirements - RECOMMENDED
Flex ATX Specific Guidelines 2.0
Flex ATX Specific Guidelines 2.0 Physical Dimensions – REQUIRED
Physical Dimensions – REQUIRED

Separate Current Limit for 12V2 - OPTIONAL

The 12 V rail on the 2x2 power connector should be a separate current limited output to meet the requirements of UL and EN 62368-1. This only applies if the PSU is trying to meet a 240VA Energy Hazard Safety Requirement, most power supplies are not currently designed to meet this requirement.

Overall Power Supply Efficiency Levels