Secondary Analysis

The FSP Aurum Xilenser 500FLD uses a synchronous design, meaning that the rectifiers were replaced with MOSFETs. Also, this power supply uses a DC-DC design, meaning that it is basically a +12 V power supply, with the +5 V and +3.3 V outputs being generated through two smaller switching power supplies connected to the +12 V rail. Both designs are used to increase efficiency.

The +12 V output uses four  IPD036N04L G MOSFETs, each supporting up to 90 A at 25° C or 87 A at 100° C in continuous mode or up to 400 A at 25° C in pulse mode, with a maximum RDS(on) of 3.6 mΩ. These transistors are located on the solder side of the printed circuit board, and the power supply case is used as a heatsink for them.

FSP Xilencer 500wFigure 17: The +12 V transistors

The DC-DC converters are located on a daughterboard and are controlled by an APW7159 integrated circuit. Each converter uses four IRLR8729PBF MOSFETs, each supporting up to 58 A at 25° C or 41 A at 100° C in continuous mode or up to 260 A at 25° C in pulse mode, with a maximum RDS(on) of 8.9 mΩ.

FSP Xilencer 500wFigure 18: The DC-DC converters

FSP Xilencer 500wFigure 19: The DC-DC converters

The outputs of this power supply are monitored by a GR8323 integrated circuit. This chip supports over voltage (OVP), under voltage (UVP), and overcurrent (OCP) protections. There are two +12 V over current protection channels, correctly matching the number of +12 V rails advertised by the manufacturer.

FSP Xilencer 500wFigure 20: Monitoring circuit

The electrolytic capacitors from the secondary are also Japanese, from Rubycon and Chemi-Con, and labeled at 105° C, as usual.

FSP Xilencer 500wFigure 21: Capacitors

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