Kingwin Lazer Platinum 850 W Power Supply Review

Secondary Analysis

As one would expect in a high-efficiency power supply, the Kingwin Lazer Platinum 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 eight IPP041N04N G MOSFETs, each one supporting up to 80 A at 100° C in continuous mode, or up to 400 A at 25° C in pulse mode, with a maximum RDS(on) of only 4.1 mΩ. The “Gold” version of this power supply uses six transistors, but they have a higher labeled current (90 A at 100° C) and lower RDS(on) (3.7 mΩ).

Figure 14: The +12 V transistors

As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters, which are located on a single printed circuit board located in the secondary section of the power supply. Each converter is controlled by one NCP1587A integrated circuit and uses four IPD060N03L G MOSFETs, which support up to 50 A at 100° C in continuous mode and up to 43 A at 25° C in pulse mode, with a maximum RDS(on) of 6 mΩ. The “Gold” version of this power supply uses similar transistors here, but with a higher RDS(on).

Figure 15: The DC-DC converters

Figure 16: The DC-DC converters

We didn’t see an integrated circuit for monitoring the power supply outputs. Since the Power Good wire and sensors were connected to the small printed circuit board where the resonant controller was attached, our best guess is that the enigmatic SF29601 controller with the aid of four operational amplifiers provided by an LM324 integrated circuit do the trick.

The electrolytic capacitors available in the secondary are also from Chemi-Con and labeled at 105° C.