ATX12V电源设计指南(PDF 43)

Contents
1. Introduction ... 6
1.1. Scope 6
1.2. Key Changes for ATX12V Version 2.0 as Compared with ATX Power Supply..6
1.2.1. Increased +12 VDC output capability 6
1.2.2. Minimum Efficiency6
1.2.3. Main Power Connector: .7
1.2.4. Separate current limit for 12V2 on the 2x2 connector: ...7
1.3 Terminology7
2. Applicable Documents . 8
3. Electrical  9
3.1. AC Input.9
3.1.1. Input Over-current Protection 9
3.1.2. Inrush Current Limiting ..9
3.1.3. Input Under-voltage ...10
3.1.4. Regulatory..10
3.1.5. Catastrophic Failure Protection .11
3.2. DC Output..11
3.2.1. DC Voltage Regulation ..11
3.2.2. Remote Sensing 12
3.2.3. Typical Power Distribution .12
3.2.4. Power Limit / Hazardous Energy Levels 17
3.2.5. Efficiency ...17
3.2.6. Output Ripple/Noise...19
3.2.7. Output Transient Response...21
3.2.8. Capacitive Load .21
3.2.9. Closed-loop Stability ..22
3.2.10. +5 VDC / +3.3 VDC Power Sequencing ..22
3.2.11. Voltage Hold-up Time..22
3.3. Timing / Housekeeping / Control 22
3.3.1. PWR_OK...23
3.3.2. PS_ON#.23
3.3.3. +5 VSB...24
3.3.4. Power-on Time ..25
3.3.5. Risetime.25
3.3.6. Overshoot at Turn-on / Turn-off.25
3.3.7. Reset after Shutdown 25
3.3.8. +5 VSB at AC Power-down25
3.4. Output Protection26
3.4.1. Over-voltage Protection .26
3.4.2. Short-circuit Protection ..26
ATX12V Power Supply Design Guide
Version 2.0
4
3.4.3. No-load Operation .26
3.4.4. Over-current Protection .26
3.4.5. Over-temperature Protection .27
3.4.6. Output Bypass ...27
4. Mechanical. 28
4.1. Labeling / Marking ..28
4.2. Physical Dimensions ..28
4.3. Airflow / Fan31
4.4. AC Connector .32
4.5. DC Connectors..32
4.5.1. ATX Main Power Connector ..34
4.5.2. +12 V Power Connector.35
4.5.3. Peripheral Connector(s).35
4.5.4. Serial ATA Power Connector.36
4.5.5. Floppy Drive Connector .36
5. Environmental ... 37
5.1. Temperature..37
5.2. Thermal Shock (Shipping)..37
5.3. Humidity.37
5.4. Altitude...37
5.5. Mechanical Shock ..38
5.6. Random Vibration...38
5.7. Acoustics ...38
6. Electromagnetic Compatibility. 39
6.1. Emissions ...39
6.2. Immunity..39
6.3. Input Line Current Harmonic Content and Line Flicker ..40
6.4. Magnetic Leakage Fields40
7. Reliability ... 41
7.1. Component De-rating .41
8. Safety . 42
8.1. North America 42
8.2. International...43
8.3. Proscribed Materials...43
ATX12V Power Supply
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