This power supply uses a synchronous design in its secondary, meaning that the diodes were replaced with transistors in order to increase efficiency.
The +12 V output is rectified using two IRLB3036 MOSFETs, each one capable of handling up to 270 A at 25° C or up to 190 A at 100° C in continuous mode, or up to 1,100 A at 25° C in pulse mode. This translates into a maximum theoretical current of 271 A at 100° C or 3,257 W! These are the same transistors used in the FSP Aurum Gold 700 W and FSP Aurum CM Gold 750 W.
Figure 13: +12 V transistors
The +5 V and +3.3 V outputs share the same circuitry and are rectified by four IPD031N03L MOSFETs, each one supporting 90 A at 100° C in continuous mode and 400 A at 25° C in pulse mode, 3.1 mΩ RDS(on). The four transistors are located on the solder side of the printed circuit board.
Figure 14: The +5 V and +3.3 V transistors
The secondary transistors are controlled by an FSP6601, another proprietary chip from FSP.
Figure 15: Synchronous controller
The secondary is monitored by a WT7579 integrated circuit, which is manufactured exclusively for FSP. This chip supports over voltage (OVP), under voltage (UVP), overcurrent (OCP), and over temperature (OTP) protections. There are four +12 V over current protection (OCP) channels, matching the number of +12 V rails advertised by the manufacturer.
Figure 16: Monitoring circuit
Some of the electrolytic capacitors used in the secondary are Japanese, from Chemi-Con, and some are from CapXon.