Intel ATX12V manual Output Ripple/Noise, Energy Star Input Power Consumption

ATX12V Power Supply Design Guide

Version 2.0

3.2.5.2. Energy Star*

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.

Table 9. Energy Star Input Power Consumption

Maximum Continuous Power Rating of Power Supply

<200 W

>200 W < 300 W

>300 W < 350 W

>350 W < 400 W

>400 W

RMS Watts from the AC line in sleep/low-power mode

<15 W

<20 W

<25 W

<30 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.

3.2.5.3. Other Low Power System Requirements

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.

3.2.6. Output Ripple/Noise

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.

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