Grounding; Closed Loop Stability; Residual Voltage Immunity In Standby Mode; Common Mode Noise - Intel S1200SPL Technical Spesification

Intel® Server Board S1200SP Family Technical Product Specification

12.1.6 Grounding

The output ground of the pins of the power supply provides the output power return path. The output
connector ground pins shall be connected to the safety ground (power supply enclosure). This grounding
should be well designed to ensure passing the max allowed Common Mode Noise levels.
The power supply shall be provided with a reliable protective earth ground. All secondary circuits shall be
connected to protective earth ground. Resistance of the ground returns to chassis shall not exceed 1.0 m.
This path may be used to carry DC current.

12.1.7 Closed loop stability

The power supply shall be unconditionally stable under all line/load/transient load conditions including
capacitive load ranges specified in Section 12.1.5. A minimum of: 45 degrees phase margin and -10dB-gain
margin is required. The power supply manufacturer shall provide proof of the unit's closed-loop stability with
local sensing through the submission of Bode plots. Closed-loop stability must be ensured at the maximum
and minimum loads as applicable.

12.1.8 Residual Voltage Immunity in Standby Mode

The power supply should be immune to any residual voltage placed on its outputs (Typically a leakage voltage
through the system from standby output) up to 500mV. There shall be no additional heat generated, nor
stressing of any internal components with this voltage applied to any individual or all outputs simultaneously.
It also should not trip the protection circuits during turn on.
The residual voltage at the power supply outputs for no load condition shall not exceed 100mV when AC
voltage is applied and the PSON# signal is de-asserted.

12.1.9 Common Mode Noise

The Common Mode noise on any output shall not exceed 350mV pk-pk over the frequency band of 10Hz to
20MHz.
1. The measurement shall be made across a 100Ω resistor between each of DC outputs, including ground at
the DC power connector and chassis ground (power subsystem enclosure).
2. The test set-up shall use a FET probe such as Tektronix model P6046 or equivalent.
12.1.10

Soft Starting

The Power Supply shall contain control circuit which provides monotonic soft start for its outputs without
overstress of the AC line or any power supply components at any specified AC line or load conditions.
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Table 57. Capacitive Loading Conditions
Output MIN
+12VSB 20
+12V 500
MAX Units
3100 F
25000 F