Rosewill FORTRESS-650 Power Supply Review

Secondary Analysis

The Rosewill FORTRESS-650 uses a synchronous design, meaning that the rectifiers were replaced with MOSFETs. Also, this power supply uses a DC-DC design, meaning that it is basically a +12 V power supply, with the +5 V and +3.3 V outputs being generated through two smaller switching power supplies connected to the +12 V rail. Both designs are used to increase efficiency.

The +12 V output uses four IPP023N04N G MOSFETs, each supporting up to 90 A at 100° C in continuous mode or 400 A at 25° C in pulse mode, with a maximum RDS(on) of 2.3 mΩ.

Figure 16: Two of the four +12 V rectifiers and the +5VSB rectifier

As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters. Both are located on the same daughterboard, and each is managed by a CAT7523 PWM controller and uses a pair of MOSFETs. Unfortunately, the manufacturer scraped off the markings of these transistors, so we couldn’t identify the exact models.

Figure 17: The DC-DC converters

Figure 18: The DC-DC converters

This power supply uses a GR8313 monitoring integrated circuit, which only supports over voltage (OVP) and under voltage (UVP) protections.

Figure 19: Monitoring circuit

The electrolytic capacitors that filter the outputs are Japanese, from Chemi-Con, and labeled at 105° C, as usual. This power supply also makes use of solid capacitors. See Figure 20.

Figure 20: Secondary capacitors