ATX Version 3 Multi Rail Desktop Platform Power Supply
Design Guide
PCIe* AIC Auxiliary Power Connectors
The PCIe CEM 5.1 specification defines three 12V Auxiliary Power Connectors to be used with PCIe Add-in Cards that apply to desktop power supplies:
- 75 W 2x3 connector
- 150 W 2x4 connector
- 600 W 12V-2x6 connector
Section Section 5.2 specifies the Mechanical information for all DC Power Connectors. Note that the Voltage Tolerance listed below is different from this Power Supply Design Guide for the Low voltage tolerance Table 4-2, the reason for the difference is allowing for voltage drop on a motherboard from the Main Power Connector to the motherboard to the PCIe* Edge Card Connector. Table 3-5 shows the voltage tolerance required to the PCIe* Add-in Card at both the motherboard edge card connector and Auxiliary Power connectors. Each Auxiliary Power Connector must have voltage pins that belong to the same +12V power converter, if multiple voltage rails exist from the PSU.
Table 3-5: Auxiliary Power Connectors Power Supply Rail Requirements - +12V Only
+12V Power Rail Characteristic | 2x3 Connector | 2x4 Connector | 12V-2x6 Connector | |||
Sustained Power2, 4 | 75 Watts | 150 Watts | 150 W5 | 300 W5 | 450 W5 | 600 W5 |
+ 12 V Voltage Range | +5% / -8% | +5% / -8% | +5% / -8% | |||
Current3, 4, 5 (Max RMS) | 6.75 Amps | 13.5 Amps | 13.75 A1,5 | 27.5 A1,5 | 41.25 A1,5 | 55 A1,5 |
Maximum sustained power (Maximum of average power in any continuous 1 second interval).
Maximum of root-mean-square (RMS) of current in any continuous 1 second interval.
The main reference limit is the maximum allowed sustained power per connector and Add-in Card type. Add-in Card and System must concurrently comply with all power and voltage and current requirements in this table for the applicable connector and other requirements in this specification for the Add-in Card type.
Maximum instantaneous and other excursions exceeding these limits are defined in Section Section 3.1 of this document.