On this page, we will take an in-depth look at the primary stage of the Antec High Current Pro 750 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.
This power supply uses two D25XB60 rectifying bridges connected in parallel, which are attached to an individual heatsink. Each bridge supports up to 25 A at 98° C. In theory, you would be able to pull up to 5,750 W from a 115 V power grid. Assuming 80% efficiency, the bridges would allow this unit to deliver up to 4,600 W without burning themselves out (or 5,175 W at 90% efficiency). Of course, we are only talking about these particular components. The real limit will depend on all the components combined in this power supply.
Figure 13: Rectifying bridges
The active PFC circuit uses two IPP60R165F MOSFETs, each one supporting up to 21 A at 25° C or 13 A at 100° C in continuous mode (note the difference temperature makes), or 61 A at 25° C in pulse mode. These transistors present a 165 mΩ maximum 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.
Figure 14: The active PFC diode and one of the active PFC transistors
The active PFC circuit is managed by an FAN6982 active PFC controller.
Figure 15: Active PFC controller
The output of the active PFC circuit is filtered by three 180 µF x 450 V Japanese electrolytic capacitors, from Chemi-Con, labeled at 105° C. They are connected in parallel and are the equivalent of one 540 µF x 450 V capacitor.
Figure 16: Capacitors
In the switching section, four STP21NM60ND MOSFETs are employed using a full-bridge, resonant configuration. Each transistor supports up to 17 A at 25° C or 10 A at 100° C in continuous mode or up to 68 A at 25° C in pulse mode, with a maximum RDS(on) of 220 mΩ.
Figure 17: One of the active PFC transistors and the four switching transistors
The switching transistors are controlled by a CM6901 controller.
Figure 18: Resonant controller
Let’s now take a look at the secondary of this power supply.