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