ATX Version 3 Multi Rail Desktop Platform Power Supply

Design Guide

ID 336521
Date 11/01/2023
Document Table of Contents

Rise Time – REQUIRED

The output voltages shall rise from 10% of nominal to within the regulation ranges specified in Table 4-2 within 0.2 ms to 20 ms (0.2 ms ≤ T2 ≤ 20 ms). The total time for Rise time of each voltage is listed in Table 4-10 as T2.

There must be a smooth and continuous ramp of each DC output voltage from 10% to 95% of its final set point within the regulation band, while loaded as specified.

The smooth turn-on requires that, during the 10% to 95% portion of the rise time, the slope of the turn-on waveform must be positive and have a value of between 0 V/ms and [Vout, nominal / 0.2] V/ms. Also, for any 5 ms segment of the 10% to 95% rise time waveform, a straight line drawn between the end points of the waveform segment must have a slope ≥ [Vout, nominal / 20] V/ms.

Figure 4-6: Rise Time Characteristics