ATX电源简介
ATX电源作用是把交流220V的电源转换为计算机内部使用的直流5V，12V的电源。
ATX电源的特点：与AT电源相比，ATX电源增加了“+3.3V、+5VSB、PS－ON
其中“+3.3V”输出主要是供内存用，而“+5VSB”、“PS－ON”输出则体现了ATX电源的特点。
ATX电源最主要的特点就是：它不采用传统的市电开关来控制电源是否工作，而是采用“+5VSB、PS－ON”的组合来实现电源的开启和关闭，只要控制“PS－ON”信号电平的变化，就能控制电源的开启和关闭。“PS－ON”小于1V伏时开启电源，大于4.5伏时关闭电源。和AT电源不一样，ATX电源除了在线路上作了一些改进，其中最重要的区别是，关机时ATX电源本身并没有彻底断电，而是维持了一个比较微弱的电流。同时它利用这一电流增加了一个电源管理功能，称为Stand-By。它可以让操作系统直接对电源进行管理。通过此功能，用户就可以直接通过操作系统实现软关机，而且还可以实现网络化的电源管理。如在电脑关闭时，可以通过网络发出信号到电脑的Modem上，然后监控电路就会发出一个ATX电源所特有的+5VSB激活电压，来打开电源启动电脑，从而实现远程开机。
下面是ATX接口的详细线序图：
24-pin ATX12V 2.x
| Color | Signal | Pin | Pin | Signal | Color | |
|---|---|---|---|---|---|---|
| Orange | +3.3 V | 1 | 13 | +3.3 V | Orange | |
| +3.3 V sense | Brown | |||||
| Orange | +3.3 V | 2 | 14 | -12 V | Blue | |
| Black | Ground | 3 | 15 | Ground | Black | |
| Red | +5 V | 4 | 16 | Power on | Green | |
| Black | Ground | 5 | 17 | Ground | Black | |
| Red | +5 V | 6 | 18 | Ground | Black | |
| Black | Ground | 7 | 19 | Ground | Black | |
| Grey | Power good | 8 | 20 | -5V | White | |
| Purple | +5 V standby | 9 | 21 | +5 V | Red | |
| Yellow | +12 V | 10 | 22 | +5 V | Red | |
| Yellow | +12 V | 11 | 23 | +5 V | Red | |
| Orange | +3.3 V | 12 | 24 | Ground | Black |
20-pin ATX connector omits the last four pin: 11, 12, 23, 24)
Pins 8, 13, and 16 are control signals:
- “Power On” is pulled up to +5V by the PSU, and must be driven low to turn on the PSU.
- “Power good” is low when other outputs have not yet reached, or are about to leave, correct voltages.
- “+3.3 V sense” line is for remote sensing of the voltage drop in the power supply wiring (should be connected to the +3.3 V on the motherboard)
“+5 V standby” supplies power even when the rest of the supply lines are off.
Pin 20 (-5V, white) is absent in current power supplies; it was optional in ATX and ATX12V ver. 1.2, and deleted as of ver. 1.3.
ATX Aux Power Cable
| Pin | Color | Function |
|---|---|---|
| 1 | Black | Ground |
| 2 | Black | Ground |
| 3 | Black | Ground |
| 4 | Orange | +3.3 V |
| 5 | Orange | +3.3 V |
| 6 | Red | +5 V |
ATX 4pin +12V Power Cable
| Color | Function | Pin | Pin | Function | Color | |
|---|---|---|---|---|---|---|
| Black | Ground | 1 | 3 | +12 V | Yellow | |
| Black | Ground | 2 | 4 | +12 V | Yellow |
ATX 8pin EPS +12V Power Cable
| Color | Function | Pin | Pin | Function | Color | |
|---|---|---|---|---|---|---|
| Black | Ground | 1 | 5 | +12 V | Yellow | |
| Black | Ground | 2 | 6 | +12 V | Yellow | |
| Black | Ground | 3 | 7 | +12 V | Yellow | |
| Black | Ground | 4 | 8 | +12 V | Yellow |
你可以把一个8pin的EPS线缆插到一个4pin 12V的主板上。
你也可以把一个4pin 12V的电源线插到一个8pin EPS主板连接器上，但是不能保证它能正常工作。
6/8pin PCI Express Power Cable
| Color | Function | Pin | Pin | Function | Color | |
|---|---|---|---|---|---|---|
| Yellow | +12 V | 1 | 5 | Ground | Black | |
| Yellow | +12 V | 2 | 6 | Ground | Black | |
| Yellow | +12 V | 3 | 7 | Ground | Black | |
| Black | Ground | 4 | 8 | Ground | Black |
6p 引脚连接器最大输出功率:75w
8p 引脚连接器最大输出功率:150 W
ATX Tolerance
| Volt | Tolerance | Range | Ripple max |
|---|---|---|---|
| +5 VDC | ±5% (±0.25 V) | +4.75 V to +5.25 V | 50 mV |
| -5 VDC | ±10% (±0.50 V) | -4.50 V to -5.50 V | 50 mV |
| +12 VDC | ±5% (±0.60 V) | +11.40 V to +12.60 V | 120 mV |
| -12 VDC | ±10% (±1.2 V) | -10.8 V to -13.2 V | 120 mV |
| +3.3 VDC | ±5% (±0.165 V) | +3.135 V to +3.465 V | 50 mV |
| +5 VSB | ±5% (±0.25 V) | +4.75 V to +5.25 V | 50 mV |
D型电源头
| Color | Function | Pin |
|---|---|---|
| Yellow | +12 V | 1 |
| Black | Ground | 2 |
| Black | Ground | 3 |
| Red | +5 V | 4 |
