Intel ATX 3.0, Design Manual

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Contents
1 Introduction .................................................................................................. 13
1.1 Alternative Low Power Mode for Power Supplies ....................................... 13
1.2 Reference Documentation ..................................................................... 13
1.3 Terminology ....................................................................................... 15
2 Processor Configurations ................................................................................. 17
2.1 Processor Configurations - RECOMMENDED ............................................. 17
2.2 High End Desktop Market Processor Considerations .................................. 17
2.2.1 Modular Power Supply Connectors ............................................ 18
2.2.2 Overclocking Recommendations ............................................... 19
3 PCI Express* Add-in Card Considerations .......................................................... 20
3.1 PCIe* Add-in Card Power Excursions ...................................................... 20
3.1.1 PCIe* Add-in Card and PSU Power Budgets ................................ 22
3.1.2 PSU Power Excursion .............................................................. 24
3.2 PCIe* AIC Auxiliary Power Connectors .................................................... 25
3.3 PCIe* Add-in Card Auxiliary Power Connectors Sideband Signals ................ 26
3.3.1 Sense1 / Sense0 (Required) .................................................... 27
3.3.2 CARD_PWR_STABLE (Optional) ................................................ 27
3.3.3 CARD_CBL_PRES# (Optional) .................................................. 28
3.3.4 Sideband Signals DC Specifications (Required) ........................... 29
4 Electrical ...................................................................................................... 30
4.1 AC Input - REQUIRED .......................................................................... 30
4.1.1 Input Over Current Protection – REQUIRED ................................ 30
4.1.2 Inrush Current – REQUIRED ..................................................... 30
4.1.3 Input Under Voltage – REQUIRED ............................................. 30
4.2 DC Output - REQUIRED ........................................................................ 31
4.2.1 DC Voltage Regulation – REQUIRED .......................................... 31
4.2.2 DC Output Current – REQUIRED ............................................... 31
4.2.3 Remote Sensing - RECOMMENDED ............................................ 33
4.2.4 Other Low Power System Requirements ..................................... 33
4.2.5 Output Ripple Noise - REQUIRED .............................................. 33
4.2.6 Capacitive Load – RECOMMENDED ............................................ 34
4.2.7 Closed Loop Stability - REQUIRED ............................................. 35
4.2.8 +5V DC / +3.3V DC Power Sequencing - REQUIRED .................... 35
4.2.9 Voltage Hold-Up Time - REQUIRED ........................................... 36
4.2.10 12V2 DC Minimum Loading - REQUIRED .................................... 36
4.3 Timing, Housekeeping and Control – REQUIRED ....................................... 36
4.3.1 PWR_OK – REQUIRED ............................................................. 37
4.3.2 Power-Up Cross Loading Condition – REQUIRED .......................... 38
4.3.3 PS_ON# – REQUIRED ............................................................. 38
4.3.4 +5VSB – REQUIRED ............................................................... 39
4.3.5 Power-On Time – REQUIRED .................................................... 40
4.3.6 Rise Time – REQUIRED............................................................ 40
4.3.7 Overshoot at Turn-On / Turn-Off – REQUIRED ............................ 41
4.4 Reset After Shutdown .......................................................................... 41
4.4.1 +5VSB at Power-Down – REQUIRED ......................................... 41
4.4.2 +5VSB Fall Time - RECOMMENDATION ...................................... 42