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Ripple Measurements
To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the SFX L Power 600W'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 | 8.1mV | 8.0mV | 11.9mV | 6.0mV | Pass |
| 20% Load | 10.7mV | 9.2mV | 14.0mV | 7.8mV | Pass |
| 30% Load | 13.7mV | 11.0mV | 17.7mV | 8.8mV | Pass |
| 40% Load | 17.3mV | 12.1mV | 18.6mV | 10.1mV | Pass |
| 50% Load | 22.0mV | 14.6mV | 19.6mV | 11.7mV | Pass |
| 60% Load | 27.6mV | 16.1mV | 21.7mV | 13.5mV | Pass |
| 70% Load | 30.3mV | 17.8mV | 25.5mV | 15.3mV | Pass |
| 80% Load | 36.1mV | 20.2mV | 27.6mV | 16.8mV | Pass |
| 90% Load | 40.0mV | 21.4mV | 30.1mV | 19.2mV | Pass |
| 100% Load | 45.9mV | 23.6mV | 31.9mV | 21.3mV | Pass |
| 110% Load | 57.4mV | 25.2mV | 35.8mV | 23.8mV | Pass |
| Cross-Load 1 | 14.1mV | 13.7mV | 18.7mV | 11.1mV | Pass |
| Cross-Load 2 | 52.8mV | 21.9mV | 30.2mV | 18.8mV | Pass |
Ripple suppression on the +12V and 3.3V rails is average, while it's fairly good on the 5V and 5VSB rails. We would like to see below 40mV ripple at +12V under full load, and close to 25mV at 3.3V under the same conditions.
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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