Intel ATX 0.9 - Manual (Page 3)

Intel ATX Power Supply Design Guide
Version 0.9
Page 3
Contents
1. Scope .................................................................................................................. 6
2. Applicable Documents ...................................................................................... 7
3. Electrical Specification ..................................................................................... 8
3.1 AC Input Requirements .........................................................................................................8
3.1.1 Input Overcurrent Protection.....................................................................................8
3.1.2 Inrush Current Limiting .............................................................................................8
3.1.3 Input Undervoltage ...................................................................................................8
3.1.4 Immunity ...................................................................................................................9
3.1.5 Catastrophic Failure Protection ................................................................................11
3.2 DC Output Requirements ......................................................................................................11
3.2.1 DC Voltage Regulation .............................................................................................11
3.2.2 Remote Sensing .......................................................................................................11
3.3 Typical Power Distribution .....................................................................................................12
3.3.1 Power Limit ...............................................................................................................13
3.3.2 Efficiency ..................................................................................................................13
3.3.3 Output Ripple/Noise..................................................................................................14
3.3.4 Output Transient Response......................................................................................14
3.3.5 Capacitive Load ........................................................................................................14
3.3.6 Closed Loop Stability ................................................................................................14
3.3.7 +5VDC/+3.3VDC Power Sequencing .......................................................................15
3.3.8 Voltage Hold-up Time ...............................................................................................15
3.4 Timing / Housekeeping / Control ...........................................................................................16
3.4.1 PWR_OK ..................................................................................................................16
3.4.2 PS_ON#....................................................................................................................17
3.4.3 +5VSB.......................................................................................................................17
3.4.4 Power-on Time .........................................................................................................17
3.4.5 Risetime....................................................................................................................18
3.4.6 Overshoot at Turn-on/Turn-off..................................................................................18
3.4.7 Reset after Shutdown ...............................................................................................18
3.4.8 +5VSB at AC Power Down .......................................................................................18
3.5 Output Protection...................................................................................................................19
3.5.1 Overvoltage Protection .............................................................................................19
3.5.2 Short Circuit Protection.............................................................................................19
3.5.3 No Load Operation ...................................................................................................19
3.5.4 Overcurrent Protection..............................................................................................19
3.5.5 Output Bypass ..........................................................................................................19
4. Mechanical Requirements ................................................................................ 20
4.1 Labeling / Marking .................................................................................................................20
4.2 Physical Dimensions..............................................................................................................20
4.3 Airflow / Fan...........................................................................................................................23