ATX12VO (12V Only) Desktop Power Supply

Design Guide

ID 613768
Date 11/01/2023
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents
Document Table of Contents
Legal Introduction Processor Configurations PCI Express* Add-in Card Considerations Electrical Mechanical Acoustics Environmental Electromagnetic Compatibility Safety Reliability CFX12V Specific Guidelines 2.1 LFX12V Specific Guidelines 2.1 ATX12V Specific Guidelines 3.1 SFX12V Specific Guidelines 4.1 TFX12V Specific Guidelines 3.1 Flex ATX Specific Guidelines 2.1
Legal
Introduction
Introduction Power Supplies and Alternative Low Power Mode System Power Telemetry Feature Reference Documentation Terminology
Power Supplies and Alternative Low Power Mode
System Power Telemetry Feature
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 12V-2x6 Auxiliary Power Connector 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 12V-2x6 Auxiliary Power Connector Sideband Signals
PCIe* Add-in Card 12V-2x6 Auxiliary Power Connector Sideband Signals SENSE0 / SENSE1 (Required) CARD_PWR_STABLE (Optional) CARD_CBL_PRES# (Optional in Power Supply) Sideband Signals DC Specifications (Required)
SENSE0 / SENSE1 (Required)
CARD_PWR_STABLE (Optional)
CARD_CBL_PRES# (Optional in Power Supply)
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 – REQUIRED Output Ripple Noise – REQUIRED Capacitive Load – RECOMMENDED Closed Loop Stability – REQUIRED Multiple 12V Rail Power Sequencing – REQUIRED Voltage Hold-Up Time – REQUIRED/RECOMMENDED
DC Voltage Regulation – REQUIRED
DC Output Current – REQUIRED
Remote Sensing – RECOMMENDED
Other Low Power System Requirements – REQUIRED
Output Ripple Noise – REQUIRED
Capacitive Load – RECOMMENDED
Closed Loop Stability – REQUIRED
Multiple 12V Rail Power Sequencing – REQUIRED
Voltage Hold-Up Time – REQUIRED/RECOMMENDED
Timing, Housekeeping, and Control – REQUIRED
Timing, Housekeeping, and Control – REQUIRED PWR_OK - REQUIRED PS_ON# - REQUIRED +12VSB – REQUIRED Power-On Time – REQUIRED Rise Time – REQUIRED Overshoot at Turn-On / Turn-Off – REQUIRED I_PSU% Signal – REQUIRED
PWR_OK - REQUIRED
PS_ON# - REQUIRED
+12VSB – REQUIRED
Power-On Time – REQUIRED
Rise Time – REQUIRED
Overshoot at Turn-On / Turn-Off – REQUIRED
I_PSU% Signal – REQUIRED
Reset After Shutdown
Reset After Shutdown +12VSB at Power-Down – REQUIRED +12VSB Fall Time – RECOMMENDED
+12VSB at Power-Down – REQUIRED
+12VSB Fall Time – RECOMMENDED
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) Connector from Motherboard to Storage Devices – Reference Airflow and Fans (Recommended)
Labeling and Marking - RECOMMENDED
Connectors (Required)
AC Connector DC Connectors
AC Connector
DC Connectors
Connector from Motherboard to Storage Devices – Reference
Connector from Motherboard to Storage Devices – Reference Motherboard Connector Serial ATA Connectors (Reference)
Motherboard Connector
Serial ATA Connectors (Reference)
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
Environmental
Environmental Temperature (Recommended) Thermal Shock (Shipping) Humidity (Recommended) Altitude (Recommended) Mechanical Shock (Recommended) Random Vibration (Recommended)
Temperature (Recommended)
Thermal Shock (Shipping)
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 2.1
CFX12V Specific Guidelines 2.1 Physical Dimensions (Required)
Physical Dimensions (Required)
LFX12V Specific Guidelines 2.1
LFX12V Specific Guidelines 2.1 Physical Dimensions (Required)
Physical Dimensions (Required)
ATX12V Specific Guidelines 3.1
SFX12V Specific Guidelines 4.1
SFX12V Specific Guidelines 4.1 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 Dimensions (Required) 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 Dimensions (Required)
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 3.1
TFX12V Specific Guidelines 3.1 Physical Dimensions (Required) Mounting Options (Recommended) Chassis Requirements (Recommended)
Physical Dimensions (Required)
Mounting Options (Recommended)
Chassis Requirements (Recommended)
Flex ATX Specific Guidelines 2.1
Flex ATX Specific Guidelines 2.1 Physical Dimensions (Required)
Physical Dimensions (Required)
Legal
Introduction
Processor Configurations
PCI Express* Add-in Card Considerations
Electrical
Mechanical
Acoustics
Environmental
Electromagnetic Compatibility
Safety
Reliability
CFX12V Specific Guidelines 2.1
LFX12V Specific Guidelines 2.1
ATX12V Specific Guidelines 3.1
SFX12V Specific Guidelines 4.1
TFX12V Specific Guidelines 3.1
Flex ATX Specific Guidelines 2.1

DC Output Current – REQUIRED

The below table summarizes the expected output transient step sizes for each output. All items in the below table are REQUIRED, unless specifically called out as RECOMMENDED.

Table 4-3: DC Output Transient Step Sizes

Output

Maximum Step Size

(% of Rated Output Amps)

Maximum Step Size (A)

+12V1DC4

40% (Required)70% (Recommended)

-

+12V2DC4

85% of CPU supported in Table 2-11

-

+12V3/44

Steps from 100% à 300% 3

30% à 100% 2

+12VSB

-

0.5

Notes:
  1. 12V2 rails are typically used for CPU power. CPU step size will have more updated values in the Power Supply Design Guide Addendum (# 621484) which will be used to determine the 85% value
  2. 12V3/V4 rails are typically used for PCIe* Add-in Card connectors. This recommendation is based on Section 3 where PCIe* Add-in Card needs are discussed. The step size will come from the amount of PCIe* Add-in Card power supported based on the size of the PSU in Table 3-2. For more detail refer Desktop Platforms Power Supply Test Plan (#338448)
  3. If a power supply has multiple 12V-2x6 connectors, Dynamic testing shall be done on each 12V-2x6 connector. For more detail refer Desktop Platforms Power Supply Test Plan (#338448)
  4. Power supplies that have one combined 12V rail shall perform Dynamic testing on the one 12V rail with multiple tests which simulate different system level workloads: 12V1 (total system), 12V2 (CPU Load), and 12V3/V4 (PCIe* AIC).

Output voltages should remain within the regulation limits of Table 4-2, for instantaneous changes in load as specified in Table 4-3 and for the following conditions:

  • Simultaneous load steps on the +12 VDC output (all steps occurring in the same direction)
  • Load-changing repetition rate of 50 Hz to 10 kHz
  • AC input range as per Section 2.1 and Capacitive loading per Table 4-7.

The transient load slew rate is defined in the Table 4-4 based on PSU supporting any PCIe* Auxiliary Power Connectors. This usually can be correlated to the PSU’s Rated Wattage, which is listed as a guidance.

Table 4-4: DC Output Transient Slew Rate

Output

PSU without PCIe* 12V-2x6 Connectors (Recommended Size ≤450 Watts)

PSU with PCIe* 12V-2x6 Connector(Recommended Size >450 Watts)

All +12V

2.5 A/µS

5.0 A/µS

+12VSB

0.1 A/µS

0.1 A/µS

Remote Sensing – RECOMMENDED