FSP Aurum 92+ 650 W Power Supply Review

Primary Analysis

On this page, we will take an in-depth look at the primary stage of the FSP Aurum 92+ 650 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.

This power supply uses a GBU15L06 rectifying bridge, which is attached to an individual heatsink. This bridge supports up to 15 A at 115° C. So in theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 W without burning itself out (or 1,553 W with 90% efficiency). Of course, we are only talking about this particular component. The real limit will depend on all the components combined in this power supply.

Figure 12: Rectifying bridge

The active PFC circuit uses two IPA60R125CP MOSFETs, each one supporting up to 25 A at 25° C or 16 A at 100° C in continuous mode (note the difference temperature makes), or 82 A at 25° C in pulse mode. These transistors present a 125 mΩ resistance when turned on, a characteristic called RDS(on). The lower the number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.

The output of the active PFC circuit is filtered by one 390 µF x 450 V Japanese electrolytic capacitor, from Chemi-Con, labeled at 105° C.

Figure 13: Capacitor

In the switching section, this power supply uses the same configuration as FSP’s Aurum Gold units, called active clamp reset forward. The switching transistor is an SPA17N80C3 MOSFET, which supports up to 17 A at 25° C or 11 A at 100° C in continuous mode, or up to 51 A at 25° C in pulse mode, with a maximum RDS(on) of 290 mΩ. A second transistor (resetting transistor) is used to turn off the switching transistor and is controlled from the secondary side. The transistor used for this function is an FQPF3N80C. 

Figure 14: Switching transistor, resetting transistor, and active PFC transistors

The primary is managed by a custom-made active PFC/PWM controller called FSP6600. Since this is a custom integrated circuit, no datasheet is available for it.

Figure 15: Active PFC/PWM controller

Let’s now take a look at the secondary of this power supply.