Protection Features Evaluation

The OCP triggering points on the minor rails (5V and 3.3V) should be set lower, to around 130%. There is no point for such high amperage on these rails because modern systems only utilize them lightly.

DC Power Sequencing

According to Intel's most recent Power Supply Design Guide (revision 1.4), the +12V and 5V rails must have voltages equal or greater than the 3.3V rail's output during power-up and regular operation. For our first measurement, we turn the unit off and switch it back on without any load on any of the rails.


As you can see in the scope shots above, the 3.3V rail is always below +12V and 5V.

EMC Pre-Compliance Testing - Average and Peak EMI Detector Results

Electromagnetic Compatibility (EMC) is the ability of a device to operate properly in its environment without disrupting the proper operation of other close-by devices.

Electromagnetic Interference (EMI) stands for the electromagnetic energy a device emits, and it can cause problems in other close-by devices if too high.



There are two high spurs that go over the limits. One is at 3998 kHz, which exceeds the Average EMI detector's corresponding limit, while the spur at 11997 kHz goes over both the Average and the Peak EMI detector's limits.