SSI America ERP2U manual Grounding, Remote Sense, Output Power/Currents, W Load Ratings

SSI

			ERP2U Power Supply Design Guide, V2.31
	1	SMBus Clock	White/Green Stripe
2		SMBus Data	White/Yellow Stripe
3		SMBAlert
4		ReturnS	Black/White Stripe
	5	3.3RS	Orange/White Stripe

6.2Grounding

STATUS

Required

The ground of the pins of the power assembly wire harness provides the power return path. The wire harness ground pins shall be connected to safety ground (power supply enclosure).

6.3Remote Sense

STATUS

Optional

The power assembly may have remote sense for the +3.3V (3.3VS) and return (ReturnS) if the Optional Server Signal connector is implemented and the module has a +3.3V output. The remote sense return (ReturnS) is used to regulate out ground drops for all output voltages. The +3.3V remote sense (3.3VS) is used to regulate out drops in the system for the +3.3 V output. The remote sense input impedance to the power sub-assembly must be greater than 200 ohms on 3.3 VS and ReturnS. This is the value of the resistor connecting the remote sense to the output voltage internal to the power assembly. Remote sense must be able to regulate out a minimum of 200 mV drop on the +3.3 V output. The remote sense return (ReturnS) must be able to regulate out a minimum of 200 mV drop in the power ground return. The current in any remote sense line shall be less than 5 mA to prevent voltage sensing errors. The power supply must operate within specification over the full range of voltage drops from the power assembly’s output connector to the remote sense points.

6.4Output Power/Currents

STATUS

Recommended

The following tables define the power and current ratings for different recommended power levels. Depending upon the system design, the power supply modules may have less outputs than required by the system (example: +12V and 5VSB). If there are less outputs than required by the system on the module, the cage shall have additional DC/DC converters to generate the voltages not produced by the modules (example: +12V/+5V, +12V/+3.3V, +12V/-12V). The combined output power of all outputs from the cage shall not exceed the rated output power. The power assembly shall meet both static and dynamic voltage regulation requirements over the full load ranges. The power sub-assembly shall supply redundant power over the full load ranges.

Voltage

+3.3 V 7

+5 V 7

Table 13: 550 W Load Ratings

Minimum Continuous	Maximum Continuous
0.8 A	24 A
0.5 A	24 A
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