Seasonic G-360 Power Supply Review

Secondary Analysis

As one would expect in a high-efficiency power supply, the Seasonic G-360 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 two PSMN2R6-40YS MOSFETs, each one supporting up to 100 A at 100° C in continuous mode, or up to 651 A at 25° C in pulse mode, with a maximum RDS(on) of 5.3 mΩ. These transistors are located on the solder side of the printed circuit board, using the power supply case as their heatsink. 

Figure 16: The +12 V transistors

As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters, which are situated on a single printed circuit board located in the secondary section of the power supply. The converters are controlled by an APW7159 integrated circuit, and each converter uses a pair of PH7030AL MOSFETs. Each transistor supports up to 76 A at 25° C or 53 A at 100° C in continuous mode and up to 260 A at 25° C in pulse mode, with a maximum RDS(on) of 7 mΩ.

Figure 17: The DC-DC converters

Figure 18: The DC-DC converters

The outputs of the power supply are monitored by an HY510N integrated circuit, which only supports over voltage (OVP) and under voltage (UVP) protections.

Figure 19: Monitoring circuit

The electrolytic capacitors available in the secondary are also Japanese, from Chemi-Con and Rubycon, and labeled at 105° C, as usual. A few solid capacitors are also used.

Figure 20: Capacitors