ATX 24 pin power supply connector pinout
24 pin MiniFit Jr 5566-24 male (MOLEX 44206-0007)connectorat the
motherboard
24 pin MiniFit Jr 5557-24 female (MOLEX 39-01-2240)connectorat
the PSU cable
ATX 2.2 and later (ATX12V 2) is common ATX standard, 24 pin
connector.
Changes to ATX standard were made to support 75 watt PCI Express
requirements. Most power is now provided on 12 V rails and the
power on 3.3 V and 5 V rails was significantly reduced. The
standard specifies that two independent 12 V rails (12 V2 for the 4
pin connector and 12 V1 for everything else) with independent
overcurrent protection are needed to meet the power
requirements.
New ATX v 2.2 uses new connector, but most motherboards nowdays
allow to use an old ATX v 1.x power supply with ATX 20 pin
connector - it connects to 24 pin motherboard receptacle.
PinNameColorDescription
13.3VOrange+3.3 VDC
23.3VOrange+3.3 VDC
3COMBlackGround
45VRed+5 VDC
5COMBlackGround
65VRed+5 VDC
7COMBlackGround
8PWR_OKGrayPower Ok is a status signal generated by the power
supply to notify the computer that the DC operating voltages are
within the ranges required for proper computer operation (+5 VDC
when power is Ok)
95VSBPurple+5 VDC Standby Voltage (max 10mA, max 2A in ATX 2.2
spec)
1012VYellow+12 VDC
1112VYellow+12 VDC
123.3VOrange+3.3 VDC
133.3VOrange+3.3 VDC.ATX V2.3 / EPS12V V2.92 both define that
the PSU has to use remote sensing to compensate cable drops on the
3.3V line. Because of this there is an additional brown cable
crimped together with the orange cable either to pin 13 (ATX) or
pin 1 (EPS12V).
14-12VBlue-12 VDC
15COMBlackGround
16/PS_ONGreenPower Supply On (active low). Short this pin to GND
to switch power supply ON, disconnect from GND to switch OFF.
17COMBlackGround
18COMBlackGround
19COMBlackGround
20-5VWhite-5 VDC (this is optional on newer ATX-2 supplies, it
is for use with older AT class expansion cards and can be omitted
on newer units)
21+5VRed+5 VDC
22+5VRed+5 VDC
23+5VRed+5 VDC
24COMBlackGround
/PSON activated by pressing and releasing the power button while
the power supply is in standby mode. Activating /PSON connects the
power supply's /PSON input to ground, thereby switching the power
supply to full-on condition.
18 AWG is recommended for all wires except pin 11, which should
be 22 AWG. For 300W configurations 16 AWG is recommended.
