ATX Version 3 Multi Rail Desktop Platform Power Supply

Design Guide

ID 336521
Date 11/01/2023
Document Table of Contents

PCIe* Add-in Card 12V-2x6 Auxiliary Power Connector Sideband Signals

The new 12V-2x6 connector carries four sideband signals that communicate between the Power Supply and the PCIe* Card. The sideband signals are:

  • SENSE0 (Required)
  • SENSE1 (Required)
  • CARD_​PWR_​STABLE (Optional)
  • CARD_​CBL_​PRES# (Required/Optional)

For the most current and detailed description of the electrical requirements of the sideband signals, refer to section 5.3 – Optional Sideband Signal in the PCI Express* Card Electromechanical Specification, Revision 5.1 (often shortened toPCIe CEM 5.1 Spec”). That document is available from Physical specifications for the 12V-2x6 Cable Plug and mating PCB Header are provided in section of this document, and are also detailed the PCIe CEM 5.1 Spec.

When multiple 12V-2x6 Auxiliary Power Connectors are present in system, their sideband conductors and the signals they carry are independent among separate connected and unconnected PCIe cards and cables.