be quiet! Dark Power Pro 10 850 W Power Supply Review

Secondary Analysis

The be quiet! Dark Power Pro 10 850 W 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. Also, the +12 V output uses a synchronous design, where the rectifiers were replaced with MOSFETs. Both designs are used to increase efficiency.

The +12 V output uses four BSC018N04LS G MOSFETs, each supporting up to 100 A at 100° C in continuous mode or 400 A at 25° C in pulse mode, with a maximum RDS(on) of 1.8 mΩ. These transistors are located on the solder side of the printed circuit board, using the power supply case as a heatsink.

Figure 16: The +12 V MOSFETs

The DC-DC converters are located on the same printed circuit board as the modular cabling system. Both are managed by an APW7159 PWM controller, with each output using three RJK0332DPB MOSFETs, each supporting up to 35 A at 25° C in continuous mode or 140 A at 25° C in pulse mode, with a maximum RDS(on) of 8.5 mΩ.

Figure 17: The DC-DC converter

Figure 18: The DC-DC converter

This power supply uses a PS232F monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. There are four +12 V over current protection (OCP) channels, matching the number of +12 V rails advertised by the manufacturer.

Figure 19: Monitoring circuit

The electrolytic capacitors that filter the outputs are also Japanese, from Chemi-Con, and labeled at 105° C, as usual. This unit also makes use of solid capacitors.