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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 SX500-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 | 24.9mV | 17.1mV | 21.9mV | 16.6mV | Pass |
| 20% Load | 36.8mV | 14.3mV | 14.4mV | 15.3mV | Pass |
| 30% Load | 24.2mV | 17.9mV | 15.4mV | 21.2mV | Pass |
| 40% Load | 23.9mV | 21.1mV | 21.4mV | 23.9mV | Pass |
| 50% Load | 23.1mV | 21.7mV | 23.9mV | 20.4mV | Pass |
| 60% Load | 25.8mV | 29.0mV | 28.9mV | 23.8mV | Pass |
| 70% Load | 29.0mV | 27.0mV | 33.1mV | 27.4mV | Pass |
| 80% Load | 30.9mV | 30.2mV | 36.0mV | 30.4mV | Pass |
| 90% Load | 31.7mV | 32.4mV | 30.8mV | 34.3mV | Pass |
| 100% Load | 35.4mV | 36.0mV | 36.5mV | 32.0mV | Pass |
| 110% Load | 37.1mV | 35.0mV | 36.6mV | 34.2mV | Pass |
| Cross-Load 1 | 32.9mV | 28.1mV | 38.2mV | 30.0mV | Pass |
| Cross-Load 2 | 34.6mV | 47.7mV | 46.8mV | 28.9mV | Pass |
Ripple suppression is good on the +12V rail and average on the minor rails, where we want to see below 30mV readings (<20mV, ideally). The 5VSB rail is close to 34mV, and we did notice a strange (small) drop on this rail during the full load test.
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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