Protection Features & DC Power Sequencing
Protection Features
Check out our PSUs 101 article to learn more about PSU protection features. Our protection features evaluation methodology is described in detail here.
| Protection Features | |
|---|---|
| OCP | 12V: 67.6A (135.2%), 11.998V 5V: 27.5A (137.5%), 5.025V 3.3V: 29.1A (145.5%), 3.312V 5VSB: 3.5A (140%), 4.956V |
| OPP | 809.49W (134.92%) |
| OTP | ✓ (145°C @ secondary side) |
| SCP | 12V: ✓ 5V: ✓ 3.3V: ✓ 5VSB: ✓ -12V: ✓ |
| PWR_OK | Accurate, but lower than 16ms |
| NLO | ✓ |
| SIP | Surge: MOV Inrush: NTC thermistor & bypass relay |
OCP levels on the +12V, 5V, and 5VSB rails are set properly. The triggering point at 3.3V is a bit higher than we would like to see. Still, the rail's voltage stays close to nominal and ripple remains well-controlled.
Over-power protection is configured correctly. Short circuit protection is present on every rail, just as we'd expect from a modern PSU. Finally, the power-good signal is accurate, though lower than the ATX spec's 16ms requirement.
Surge protection is handled by an MOV and an NTC thermistor, along with a bypass relay that safeguards against large inrush currents.
DC Power Sequencing
According to Intel’s most recent Power Supply Design Guide (revision 1.4), the +12V and 5V voltages must be equal to or greater than the 3.3V rail’s output at all times.
For our first measurement, we turn the PSU off and switch it back on without load on any of its rails. In the second test, we set the PSU to standby mode, dial in a full load, and start the PSU. In the last test, with the PSU switched off, we dial in a full load before restoring power.
The 3.3V rail behaves well; its voltage remains lower than the 5V and +12V rails in all of our tests. We did, however, notice a turn-on voltage overshoot on the +12V rail during the last test. This doesn't affect DC power sequencing, but it still shouldn't happen.
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