Xigmatek Tauro 700 W Power Supply Review

Secondary Analysis

The Xigmatek Tauro 700 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 three IRFB3206GPBF MOSFETs, each supporting up to 120 A at 25° C in continuous mode or 840 A at 25° C in pulse mode, with a maximum RDS(on) of 3 mΩ.

Figure 13: The +12 V MOSFETs

The DC-DC converters are located on two individual daughterboards. Each converter is managed by an APW7073 PWM controller, using four QM3004D MOSFETs, each supporting up to 55 A at 25° C or 45 A at 100° C in continuous mode or 110 A at 25° C in pulse mode, with a maximum RDS(on) of 14 mΩ.

Figure 14: One of the DC-DC converters

Figure 15: One of the DC-DC converters

This power supply uses a PS223 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. Even though this chip provides two +12 V over current channels, the manufacturer decided to configure this unit as a single-channel model.

Figure 16: Monitoring circuit

The electrolytic capacitors that filter the outputs are from Teapo and JunFu and labeled at 105° C, as usual.