ATX12V Power Supply Design Guide
Version 2.0
3.2.3.1. ATX12V Configurations
Table 3. Typical Power Distribution for a 250 W ATX12V Configuration
|
| Min. | Max. | Peak |
|
| Current | Current | Current |
Output | (amps) | (amps) | (amps) | |
|
|
|
| |
+12 V1DC | 1 | 8 | 10 | |
|
|
|
| |
+12 V2DC | 1 | 14 |
| |
|
|
|
| |
+5 VDC | 0.3 | 18 |
| |
|
|
|
|
|
+3.3 | VDC | 0.5 | 17 |
|
|
|
|
|
|
VDC | 0 | 0.3 |
| |
|
|
|
| |
+5 VSB | 0 | 2 | 2.5 | |
|
|
|
|
|
Note: Total combined output of 3.3 V and 5 V is î:
Peak currents may last up to 17 seconds with not more than one occurrence per minute
12V1DC and 12V2DC should have separate current limit circuits to meet 240VA safety requirements.
|
|
|
| 250W Cross Regulation | ||
|
|
|
| (5V rail + 3.3V rail vs. 12V) | ||
| 120 |
|
|
|
|
|
(watts) | 100 |
|
|
|
|
|
80 |
|
|
|
|
| |
power |
|
|
|
|
| |
60 |
|
|
| C |
| |
|
|
|
|
| ||
+ 3.3V |
|
|
|
|
| |
40 |
|
|
|
|
| |
20 |
|
|
|
|
| |
5V |
|
|
|
|
| |
|
|
|
|
|
| |
| 0 |
|
|
|
|
|
| 0 | 50 | 100 | 150 | 200 | 250 |
12V power (watts)
Combined Power (5V rail + 3.3V rail)
Figure 1. Cross Loading Graph for 250W Configuration
13
