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Protection Features and 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: 71A (131.24%), 11.935V 5V: 25.1A (125.5%), 5.059V 3.3V: 27.3A (136.5%), 3.241V 5VSB: 4.3A (172%), 4.92V |
| OPP | 879.98W (135.38.2%) |
| OTP | ✓ (150°C @ secondary side) |
| SCP | 12V: ✓ 5V: ✓ 3.3V: ✓ 5VSB: ✓ -12V: ✓ |
| PWR_OK | Accurate, but less than 16ms |
| NLO | ✓ |
| SIP | Surge: MOV Inrush: NTC thermistor & bypass relay |
The OCP thresholds are set properly, and the same goes for over-power protection. Moreover, the over-temperature protection feature's triggering point is configured reasonably. Naturally, all rails are protected against short circuits.
Although the power-good signal is accurate, it falls under the 16ms limit required by the ATX specification.
An MOV helps absorb spikes and voltage surges coming from the mains grid, while an NTC thermistor and bypass relay lower inrush currents during the PSU's start-up phase.
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's voltage is always lower than the 12V and 5V rails. Also, the time difference between the 3.3V and 12V rails reaching the corresponding minimum in-regulation levels is less than 20ms, as the ATX spec requires.
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