ATX12V Power Supply Design Guide
Version 2.0
5
Figures
Figure 1. Cross Loading Graph for 250W Configuration .......................................................................13
Figure 2. Cross Loading Graph for 300W Configuration .......................................................................14
Figure 3. Cross Loading Graph for 350W Configuration .......................................................................15
Figure 4. Cross Loading Graph for 400W Configuration .......................................................................16
Figure 5. Differential Noise Test Setup .................................................................................................20
Figure 6. Power Supply Timing .............................................................................................................22
Figure 7. PS_ON# Signal Characteristics.............................................................................................24
Figure 8. Power Supply Dimensions for Chassis That Does Not Require Top Venting .......................29
Figure 9. Power Supply Dimensions for Chassis That Require Top Venting........................................30
Figure 10. ATX12V Power Supply Connectors .....................................................................................33
Figure 11. Serial ATA Connector ...........................................................................................................36
Tables
Table 1. AC Input Line Requirements...................................................................................................9
Table 2. DC Output Voltage Regulation................................................................................................11
Table 3. Typical Power Distribution for a 250 W ATX12V Configuration..............................................13
Table 4. Typical Power Distribution for a 300 W ATX12V Configuration..............................................14
Table 5. Typical Power Distribution for a 350 W ATX12V Configuration..............................................15
Table 6. Typical Power Distribution for a 400 W ATX12V Configuration..............................................16
Table 7. Minimum Efficiency Vs Load...................................................................................................17
Table 8. Loading Table for Efficiency Measurements...........................................................................18
Table 9. Energy Star Input Power Consumption...................................................................................19
Table 10. DC Output Noise/Ripple........................................................................................................20
Table 11. DC Output Transient Step Sizes...........................................................................................21
Table 12. Output Capacitive Loads.......................................................................................................21
Table 13. PWR_OK Signal Characteristics ..........................................................................................23
Table 14. PS_ON# Signal Characteristics ............................................................................................24
Table 15. Overvoltage Protection .........................................................................................................26
Table 16. Harmonic Limits, Class D Equipment ...................................................................................40
