Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the insides of a PSU better.



This is an interesting platform by FSP. There are no heat sinks on the secondary side, which reminds me of CWT designs since the FETs that regulate the +12 V rail are on the solder side of the main PCB. FSP used many daughter-boards to increase clearances between parts installed on the main PCB. This improves airflow, and the fan doesn't have to spin at high speeds to cool down the parts. The bridgeless APFC is something you won't readily find in this category because of the higher implementation cost. It provides significant energy savings, however. The next step would be to utilize a totem-pole APFC converter, but doing so necessitates a fully digital design.


The transient/EMI filter stages include all the necessary components.


The MOV is not covered in heat shrink. I guess FSP is absolutely certain it won't be damaged and blow apart inside the PSU.


The NTC thermistor and bypass relay combination is for suppressing large inrush currents.


Instead of bridge rectifiers, FETs to fully rectify the incoming AC signal are used. The diodes shown in the photos above are for the independent standby circuit.


The APFC converter uses two Infineon FETs and a pair of CREE boost diodes. The bulk caps are by Chemi-Con and have enough combined capacity to provide a hold-up time of over 17 ms.


The APFC controller is an Infineon ICE2PCS02 IC, installed on a daughter-board.


The main FETs are installed in a full-bridge topology. Two Silicon Labs Si8233BD ICs are used to drive these.


The LLC resonant controller is a Champion CU6901T2X.


The unit's main transformer is positioned far from the electrolytic filtering caps on the secondary side, which is good because it prevents its high operating temperature from straining those caps.


The FETs that regulate the +12 V rail are installed on the solder side of the main PCB.


Two DC-DC converters generate the minor rails. They use six Infineon FETs, and their joint PWM controller is an Anpec APW7159C. I also found the supervisor IC, a Weltrend WT7527RA, on the same board as the VRMs.


The filtering caps are provided by Japanese manufacturers Chemi-Con and Rubycon. Besides electrolytic caps, a large number of polymer ones are also used for ripple-filtering purposes.


The 5VSB circuit uses a CET CEB04N7G FET on its primary side and a Nexperia PSMN2R0-30YL FET on its secondary side, and the standby PWM controller is a Grenergy GR8837C IC.


Polymer caps cover the face of the modular PCB.


Soldering quality is decent, but definitely not the best I have seen from FSP.


The cooling fan is a be quiet! BQ SIW3-13525-HF. It has a diameter of 135 mm and uses a fluid dynamic bearing. Its frameless design increases airflow while keeping noise output low.