ATX Version 3 Multi Rail Desktop Platform Power Supply
Design Guide
DC Voltage Regulation – REQUIRED
The DC output voltages are required to remain within the regulation ranges shown in Table 4-2, when measured at the load end of the output connectors under all line, load, and environmental conditions specified in Chapter 7.
The lower voltage range for 12V is allowed to be -7% to allow for the power excursion requirements now described in Section Section 3.1. To compensate for these power excursions the nominal voltage could be changed to 12.1 or 12.2 Volts, depending on Power Supply design.
Table 4-2: DC Output Voltage Regulation
Output | Range | Min | Nom | Max | Unit |
+12V1DC2 | +5% / -7% | +11.20 | +12.00 | +12.60 | V |
+12V2DC2 | +5% / -7% | +11.20 | +12.00 | +12.60 | V |
+5VDC | ±5% | +4.75 | +5.00 | +5.25 | V |
+3.3VDC | ±5% | +3.14 | +3.30 | +3.47 | V |
-12VDC3 | ±10% | -10.80 | -12.00 | -13.20 | V |
+5VSB | ±5% | +4.75 | +5.00 | +5.25 | V |
+12V1DC and +12V2DC requirement applies to all +12V power rails
-12VDC output is optional