ATX12VO (12V Only) Desktop Power Supply

Design Guide

ID 613768
Date 01/03/2022
Public

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Output Ripple Noise (Required)

The output ripple and noise requirements listed in the Table 4-6 must be met throughout the load ranges specified for the appropriate form factor and under all input voltage conditions as specified in Table 4-1.

Ripple and noise are defined as periodic or random signals over a frequency band of 10 Hz to 20 MHz. Measurements must be made with an oscilloscope with 20 MHz of bandwidth. Outputs should be bypassed at the connector with a 0.1μF ceramic disk capacitor and a 10 μF electrolytic capacitor to simulate system loading. Refer to Figure 4-1 for the differential noise measurement setup.

Table 4-6: DC Output Noise/Ripple

Output

Maximum Ripple and Noise (mV p-p)

+12V1DC

120

+12V2DC

120

+12VSB

120

Figure 4-1: Differential Noise Test Setup

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