Enermax Triathlor FC 650 W Power Supply Review

Secondary Analysis

The Enermax Triathlor FC 650 W uses a synchronous design, where the Schottky rectifiers are replaced with MOSFETs. Also, the reviewed product uses a DC-DC design in its secondary. This means that the power supply is basically a +12 V unit, with the +5 V and +3.3 V outputs produced by two smaller power supplies connected to the main +12 V rail. Both designs are used to increase efficiency.

The +12 V output uses four CEP6056 MOSFETs, each one supporting up to 100 A at 25° C in continuous mode, or up to 360 A at 25° C in pulse mode, with a maximum RDS(on) of 6.2 mΩ.

Figure 15: The +12 V transistors

As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters, each one located on an individual daughterboard. Each converter is controlled by an APW7073 integrated circuit and makes use of three CEB75A3 transistors, each one supporting 69 A at 25° C in continuous mode or 276 A at 25° C in pulse mode, with a 13 mΩ maximum RDS(on).

Figure 16: One of the DC-DC converters

Figure 17: One of the DC-DC converters

The outputs are monitored by a WT7527 integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP). There are two +12 V over current protection (OCP) channels, matching the number of +12 V rails advertised by the manufacturer.

Figure 18: Monitoring circuit

This power supply uses a mix of solid and electrolytic capacitors in its secondary. The electrolytic capacitors are Japanese, from Chemi-Con, and labeled at 105° C, as usual.

Figure 19: Capacitors