Intel ATX12V Benutzerhandbuch

ATX12V Power Supply Design Guide 

Version 2.0  

 

19

The “Energy Star” efficiency requirements of the power supply depend on the intended 
system configuration.  In the low-power / sleep state (S1 or S3) the system should consume 
power in accordance with the values listed inTable 9. 

< 200 W 

< 15 W 

> 200 W < 300 W 

< 20 W 

> 300 W < 350 W 

< 25 W 

> 350 W < 400 W 

< 30 W 

> 400 W 

10% of the maximum continuous output rating 

Note:  To help meet the “Energy Star” system requirements, it is recommended that the 
power supply have > 50% efficiency in standby mode. 

For power supplies designed for low standby power, the following provides some general 
guidance.  Requirements will vary with geographic region and target end user market. 

To help meet the Blue Angel

*

, RAL-UZ 78, US Presidential executive order 13221, future 

EPA requirements, and other low Power system requirements the +5 VSB standby supply 
should be as efficient as possible.   Standby efficiency is measured with the main outputs off 
(PS_ON# high state).  Standby efficiency should be greater than 50% with a minimum 
loading of 100mA.  

The output ripple/noise requirements listed in Table 10 should be met throughout the load 
ranges specified in Section 3.2.3 and under all input voltage conditions as specified in 
Section 3.1. 

Ripple and noise are defined as periodic or random signals over a frequency band of 10 Hz 
to 20 MHz.  Measurements shall be made with an oscilloscope with 20 MHz bandwidth.  
Outputs should be bypassed at the connector with a 0.1 µF ceramic disk capacitor and a 
10 µF electrolytic capacitor to simulate system loading.  See Figure 5.