ATX Version 3.0 Multi Rail Desktop Platform Power Supply

Design Guide

ID 336521
Date 01/02/2022
Version 2.0
Public
Document Table of Contents

PCI-Express* (PCIe*) Add-in Card Connectors (Recommended)

These are optional connectors for the power supply to support additional power needed by any PCI Express** Add-in Card (AIC). The most common PCIe* Add-in Card that uses these connectors are discrete graphics cards. The PCIe* CEM Specification defines different connectors based on the power used by the Add-in Card which can range from 75 watts up to 600 watts.

PCI Express* (PCIe*) 2x3 Auxiliary Power Connector (Recommended)

The 2x3 Power Connector is designed to provide 75 watts to the PCIe* Add-in Cards and has the following requirements:

  • Current Rating: 8.0 A/pin/position maximum to a 30 °C T-Rise above ambient temperature conditions at +12 VDC, all six contacts energized.
  • Mated Connector Retention: 30.00 N minimum when plug pulled axially.

Cable Assembly Contact and Housing Details:

  • Housing Material: Thermoplastic
  • Pin Contact Base Material: Brass alloy or equivalent
  • Pin Contact Plating: Sn alloy
  • Flammability: UL94V-1 Minimum - Material certification or certificate of compliance is required with each lot to satisfy the Underwriters Laboratories follow-up service requirements.
  • Lead Free Soldering: Connector must be compatible with lead free soldering process

Table 5-4: PCIe* 2x3 Auxiliary Power Connector Pin Assignment (75 Watts)

Pin

Signal

Color1

Pin

Signal

Color1

1

+12V3/V4

Yellow

4

COM

Black

2

+12V3/V4

Yellow

5

Sense

Black

3

+12V3/V4

Yellow

6

COM

Black

    1. Wire Size: 18 AWG
    2. The Sense pin on the 2x3 auxiliary power connector must be connected to ground either directly in the power supply or via a jumper to an adjacent ground pin in the connector. This pin is used by a PCI Express* 2x3 150 W/225 W/300 W Add-in Card to detect whether the 2x3 auxiliary power connector is attached.

PCI Express* (PCIe*) 2x4 Auxiliary Power Connector (Recommended)

The 2x4 Auxiliary Power Connector consists of a PCB_​ Header, mounted on a PCIe* Add-in Card, and a mating 2x4 Cable Plug harness. The 2x4 PCB header is designed to accept both the mating 2x4 Cable Plug as well as the 2x3 cable plug, for backward-compatibility. The Add-in Card PCB Header is keyed to ensure that a 2x3 cable plug from a PSU will be properly aligned when it is mated with a 2x4 PCB Header. Two Sense pins in the 2x4 PCB header allow the PCIe* Add-in Cards to detect the power available from the cable. The 2x4 Cable Plug asserts (grounds) two sense pins to indicate that 150 watts are available to the PCIe* Add-in Card through this cable, while the 2x3 plug asserts only one sense pin, to signal that only 75 W may be drawn from the cable. The 2x4 Cable Plug has the following requirements:

  • Current Rating: 7.0 A per pin/position maximum to a 30°C T-Rise above ambient temperature conditions at +12 VDC with all eight contacts energized
  • Mated Connector Retention: 30.00 N minimum when plug pulled axially

Cable Assembly Contact and Housing Details:

  • Housing Material: Thermoplastic; Note that this connector has unique mechanical keying to avoid wrongful insertion of cable plug meant for different types of connectors.
  • Pin Contact Base Material: Brass alloy or equivalent
  • Pin Contact Plating: Sn alloy
  • Flammability: UL94V-1 Minimum - Material certification or certificate of compliance is required with each lot to satisfy the Underwriters Laboratories follow-up service requirements.
  • Lead Free Soldering: Connector must be compatible with lead free soldering process

Table 5-5: PCIe* 2x4 Auxiliary Power Connector Pin Assignment (150 Watts)

Pin

Signal

Color1

Pin

Signal

Color1

1

+12V3/V4

Yellow

5

COM

Black

2

+12V3/V4

Yellow

6

Sense0

Black

3

+12V3/V4

Yellow

7

COM

Black

4

Sense1

Black

8

COM

Black

Note:18 AWG wire.

Table 5-6: PCIe* 2x4 Auxiliary Power Connector Sense Pin Decoding by AIC

Sense 1

Sense 0

Description

Ground

Ground

A 2x4 connector is plugged into the card. The card can draw up to 150 W from the auxiliary power connector

Ground

Open

Reserved

Open

Ground

A 2x3 connector is plugged into the card. The card can only draw up to 75 W from the auxiliary power connection

Open

Open

No auxiliary power connector is plugged in

For a sense pin that needs to be grounded, it must be connected to ground either directly in the power supply or via a jumper to an adjacent ground pin in the connector

PCI Express* (PCIe*) 12VHPWR Auxiliary Power Connector (Optional for PSU ≤ 450 Watts, Required for PSU > 450 Watts)

The 12VHPWR Auxiliary Power connector is designed to deliver up to 600 watts directly to a PCIe* Add-in Cards. This power connector is not compatible with the existing 2x3 or 2x4 auxiliary power connectors. The 12VHPWR connector power pins have a 3.0 mm spacing while the contacts in a 2x3 and 2x4 connector are on a larger 4.2 mm pitch. The 12VHPWR auxiliary power connector includes twelve large contacts to carry the power and four smaller contacts beneath carrying the sideband signals.

The connector performance requirements are as follows:

  • Power Pin Current Rating: (Excluding sideband contacts) 9.2 A per pin/position with a limit of a 30 °C T-Rise above ambient temperature conditions at +12 VDC with all twelve contacts energized. The connector body must display a label or embossed H+ character to indicate support of 9.2 A/pin or greater. Refer for the approximate positioning of the marker on the 12VHPWR Right Angle (R/A) PCB Header.

• Mated Connector Latch Retention: 45.00 N minimum when plug pulled axially.

Figure 5-3: 12VHPWR Cable Plug Connector

image13.png

Figure 5-4: 12VHPWR Cable Assembly

image14.png

The cable plug connector housing for the 12VHPWR connector has all dimensions shown in mm. Slight changes to this connector that does not affect matting with its associated plug may happen. Reference latest PCI-SIG documentation for latest information about this connector.

12VHPWR Cable Plug Assembly Contact and Housing Details:

  • Housing Material: Thermoplastic Glass Fiber Filled, UL94V-0
  • Color: Black
  • Pin Contact Material: Copper Alloy
  • Power Pin Contact Plating: Tin plated on contact area
  • Signal Pin Contact Plating: Tin plated on contact area
  • All dimensions are in mm
  • Connector must be compatible with lead-free soldering process.

Wire Details:

  • Power/Ground Pin Wire Size: 16 AWG
    • All 12 pins must be connected to the power supply using 16 AWG cable
  • Sideband Signals Pin Wire Size: 28 AWG

Table 5-7: PCIe* 12VHPWR Auxiliary Power Connector Pin Assignment (600 Watts)

Pin

Signal

Color1

Pin

Signal

Color1

1

+12V3/V4

Yellow

7

COM

Black

2

+12V3/V4

Yellow

8

COM

Black

3

+12V3/V4

Yellow

9

COM

Black

4

+12V3/V4

Yellow

10

COM

Black

5

+12V3/V4

Yellow

11

COM

Black

6

+12V3/V4

Yellow

12

COM

Black

S1

CARD_​PWR_​STABLE

Blue

S3

SENSE0

Blue

S2

CARD_​CBL_​PRES#

Blue

S4

SENSE1

Blue

The electrical function for the sideband pins S1- S4 is detailed in Section Section 3.3 of this document.