Kingwin Power Force 850 W Power Supply Review

Secondary Analysis

The Kingwin Power Force 850 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 AOT480 MOSFETs, each one supporting up to 180 A at 25° C or 134 A at 100° C in continuous mode, or up to 500 A at 25° C in pulse mode, with a maximum RDS(on) of 5.5 mΩ.

Figure 16: Two of the +12 V transistors and the +5VSB diode

As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters, each located on an individual printed circuit board. Each converter is controlled by an FP6329 integrated circuit and uses four IPD060N03L G MOSFETs, each one supporting up to 50 A at 100° C in continuous mode, and up to 350 A at 25° C in pulse mode, with a maximum RDS(on) of 6 mΩ. 

Figure 17: One of the DC-DC converters

Figure 18: One of the DC-DC converters

The outputs of the power supply are monitored by a PS223 integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. This chip offers four +12 V channels, but the manufacturer decided to use only one of them, resulting in this unit having a single +12 V rail.

Figure 19: Monitoring circuit

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

Figure 20: Capacitors