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Protection Features, DC Power Sequencing, Cross-Load Tests and Infrared Images

Protection Features

Check out our PSUs 101 article to learn more about PSU protection features.

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Protection Features	Row 0 - Cell 1
OCP (Cold @ 22.5°C)	12V: 64.2A (118.89%), 12.052V 5V: 28.8A (144%), 5.029V 3.3V: 27.6A (138%), 3.307V 5VSB: 3.8A (152%), 5.011V
OCP (Hot @ 36°C)	12V: 62.2A (115.19%), 12.056V 5V: 27.7A (138.5%), 5.034V 3.3V: 27.1A (135.5%), 3.309V 5VSB: 3.8A (152%), 5.011V
OPP (Cold @ 21°C)	821.9W (126.45%)
OPP (Hot @ 38°C)	772.35W (118.82%)
OTP	✓ (114°C @ 12V Heat Sink)
SCP	12V to Earth: ✓ 5V to Earth: ✓ 3.3V to Earth: ✓ 5VSB to Earth: ✓ -12V to Earth: ✓
PWR_OK	Accurate but lower than 16ms
NLO	✓
SIP	Surge: MOV Inrush: NTC Thermistor

OCP is correctly set at 12V, and the same goes for OPP. This is not the case, though, for the minor rails where the OCP triggering points are high.

All the rest protections are present and operate well. It would be great to see a bypass relay for the NTC thermistor, but this would increase the production cost.

DC Power Sequencing

According to Intel’s most recent Power Supply Design Guide (revision 1.4), the +12V and 5V outputs must be equal to or greater than the 3.3V rail at all times. Unfortunately, Intel doesn't mention why it is so important to always keep the 3.3V rail's voltage lower than the levels of the other two outputs.

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XPG Pylon 650 — (Image credit: Tom's Hardware)

DC Power Sequencing Scope Shots

No problems here since the 3.3V rail is always lower than the other two.

Cross Load Tests

To generate the following charts, we set our loaders to auto mode through custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V, and 3.3V rails. The deviations in each of the charts below are calculated by taking the nominal values of the rails (12V, 5V, and 3.3V) as point zero. The ambient temperature during testing was between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).

Load Regulation Charts

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Load Regulation Graphs

Efficiency Graph

Ripple Graphs

The lower the power supply's ripple, the more stable the system will be and less stress will also be applied to its components.

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Ripple Suppression Graphs

Infrared Images

We apply a half-load for 10 minutes with the PSU's top cover and cooling fan removed before taking photos with a modified FLIR E4 camera able to deliver an IR resolution of 320x240 (76,800 pixels).

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IR Images

The internal temperatures are low. The bridge rectifier goes up to 72 degrees Celsius while the NTC thermistor gets even hotter to minimize its resistance.

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