To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the DQ850-M’s rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V, and 5VSB).
Test | 12V | 5V | 3.3V | 5VSB | Pass/Fail |
10% Load | 9.6 mV | 12.4 mV | 11.4 mV | 7.4 mV | Pass |
20% Load | 12.6 mV | 13.3 mV | 13.0 mV | 8.4 mV | Pass |
30% Load | 11.7 mV | 13.8 mV | 13.0 mV | 9.5 mV | Pass |
40% Load | 13.0 mV | 13.6 mV | 13.8 mV | 10.3 mV | Pass |
50% Load | 13.0 mV | 14.6 mV | 15.0 mV | 11.5 mV | Pass |
60% Load | 11.9 mV | 15.1 mV | 15.7 mV | 13.2 mV | Pass |
70% Load | 11.4 mV | 17.3 mV | 17.5 mV | 19.1 mV | Pass |
80% Load | 12.4 mV | 17.6 mV | 19.6 mV | 21.4 mV | Pass |
90% Load | 12.4 mV | 17.4 mV | 20.8 mV | 18.4 mV | Pass |
100% Load | 19.9 mV | 18.2 mV | 21.9 mV | 22.5 mV | Pass |
110% Load | 19.3 mV | 18.7 mV | 22.5 mV | 25.0 mV | Pass |
Crossload 1 | 17.4 mV | 14.6 mV | 21.3 mV | 6.5 mV | Pass |
Crossload 2 | 18.3 mV | 17.5 mV | 16.3 mV | 17.0 mV | Pass |
The ripple suppression is good overall, despite the lack of extra filtering caps on the modular cables.
Ripple Oscilloscope Screenshots
The following oscilloscope screenshots illustrate the AC ripple and noise registered on the main rails (+12V, 5V, 3.3V and 5VSB). The bigger the fluctuations on the screen, the bigger the ripple/noise. We set 0.01 V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.