Ripple Measurements
To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the SX650-G’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 | 14.5mV | 12.0mV | 14.2mV | 13.1mV | Pass |
20% Load | 58.7mV | 22.4mV | 14.3mV | 17.1mV | Pass |
30% Load | 31.4mV | 26.1mV | 19.4mV | 25.0mV | Pass |
40% Load | 29.3mV | 32.5mV | 20.0mV | 22.8mV | Pass |
50% Load | 29.7mV | 29.1mV | 20.7mV | 24.6mV | Pass |
60% Load | 29.8mV | 28.1mV | 25.3mV | 26.1mV | Pass |
70% Load | 31.7mV | 31.3mV | 27.5mV | 33.0mV | Pass |
80% Load | 34.1mV | 32.6mV | 28.5mV | 30.0mV | Pass |
90% Load | 38.4mV | 32.2mV | 30.7mV | 32.6mV | Pass |
100% Load | 44.4mV | 32.8mV | 33.0mV | 29.6mV | Pass |
110% Load | 43.8mV | 28.7mV | 31.0mV | 28.8mV | Pass |
Cross-Load 1 | 60.2mV | 25.2mV | 24.6mV | 33.7mV | Pass |
Cross-Load 2 | 41.4mV | 27.9mV | 25.6mV | 25.1mV | Pass |
The ripple suppression we measured is decent for an SFX power supply. In such a small platform, there isn't much space for extra filtering capacitors. Although it'd probably be a good idea to use cables with built-in caps, we don't like the extra bulk that those cable create.
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.
Ripple At Full Load
Ripple At 110-Percent Load
Ripple At Cross-Load 1
Ripple At Cross-Load 2
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