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Transient Response Tests, Ripple Measurements and EMC Pre-Compliance Testing
Advanced Transient Response Tests
For details on our transient response testing, please click here.
In the real world, power supplies are always working with loads that change. It's of immense importance, then, for the PSU to keep its rails within the ATX specification's defined ranges. The smaller the deviations, the more stable your PC will be with less stress applied to its components.
We should note that the ATX spec requires capacitive loading during the transient rests, but in our methodology we chose to apply the worst case scenario with no extra capacitance on the rails.
Advanced Transient Response at 20 Percent – 200ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.166V | 12.075V | 0.75% | Pass |
| 5V | 5.050V | 5.001V | 0.97% | Pass |
| 3.3V | 3.356V | 3.285V | 2.12% | Pass |
| 5VSB | 5.036V | 5.001V | 0.69% | Pass |
Advanced Transient Response at 20 Percent – 20ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.166V | 12.041V | 1.03% | Pass |
| 5V | 5.051V | 4.993V | 1.15% | Pass |
| 3.3V | 3.356V | 3.269V | 2.59% | Pass |
| 5VSB | 5.037V | 4.999V | 0.75% | Pass |
Advanced Transient Response at 20 Percent – 1ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.165V | 12.071V | 0.77% | Pass |
| 5V | 5.052V | 4.993V | 1.17% | Pass |
| 3.3V | 3.357V | 3.262V | 2.83% | Pass |
| 5VSB | 5.038V | 4.987V | 1.01% | Pass |
Advanced Transient Response at 50 Percent – 200ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.158V | 12.128V | 0.25% | Pass |
| 5V | 5.044V | 4.997V | 0.93% | Pass |
| 3.3V | 3.353V | 3.279V | 2.21% | Pass |
| 5VSB | 5.023V | 4.975V | 0.96% | Pass |
Advanced Transient Response at 50 Percent – 20ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.158V | 12.107V | 0.42% | Pass |
| 5V | 5.044V | 4.989V | 1.09% | Pass |
| 3.3V | 3.353V | 3.264V | 2.65% | Pass |
| 5VSB | 5.024V | 4.977V | 0.94% | Pass |
Advanced Transient Response at 50 Percent – 1ms
| Voltage | Before | After | Change | Pass/Fail |
|---|---|---|---|---|
| 12V | 12.157V | 12.113V | 0.36% | Pass |
| 5V | 5.045V | 4.989V | 1.11% | Pass |
| 3.3V | 3.354V | 3.262V | 2.74% | Pass |
| 5VSB | 5.025V | 4.962V | 1.25% | Pass |
The results from each rail are very good. Particularly on the all-important +12V rail, registered deviations are low.
Turn-On Transient Tests
In the next set of tests, we measure the PSU's response in simpler transient load scenarios—during its power-on phase. Ideally, we don't want to see any voltage overshoots or spikes since those put a lot of stress on the DC-DC converters of installed components.
There aren't any notable spikes or voltage overshoots to report, so everything checks out.
Ripple Measurements
| Test | 12V | 5V | 3.3V | 5VSB | Pass/Fail |
|---|---|---|---|---|---|
| 10% Load | 12.5mV | 9.7mV | 12.9mV | 10.7mV | Pass |
| 20% Load | 13.0mV | 5.2mV | 10.8mV | 12.7mV | Pass |
| 30% Load | 6.7mV | 5.0mV | 10.1mV | 9.1mV | Pass |
| 40% Load | 7.7mV | 6.4mV | 9.1mV | 7.3mV | Pass |
| 50% Load | 8.4mV | 5.0mV | 8.7mV | 7.2mV | Pass |
| 60% Load | 8.8mV | 5.2mV | 9.0mV | 7.4mV | Pass |
| 70% Load | 9.7mV | 5.3mV | 9.1mV | 8.2mV | Pass |
| 80% Load | 10.4mV | 5.5mV | 9.8mV | 8.5mV | Pass |
| 90% Load | 10.9mV | 5.6mV | 10.1mV | 8.4mV | Pass |
| 100% Load | 15.2mV | 6.5mV | 10.7mV | 9.6mV | Pass |
| 110% Load | 15.7mV | 6.6mV | 11.0mV | 9.9mV | Pass |
| Cross-Load 1 | 15.2mV | 5.2mV | 11.6mV | 7.0mV | Pass |
| Cross-Load 2 | 15.1mV | 6.2mV | 9.5mV | 9.0mV | Pass |
Ripple At Full Load
Ripple At 110-Percent Load
Ripple At Cross-Load 1
Ripple At Cross-Load 2
EMI Results – Average & Peak Detector
The EMI emissions we observe remain much lower than their allowable limits. Obviously, the AX1000's EMI filter does its job well.
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