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 a new CWT platform made for be quiet!. It has a clean design without any cables blocking airflow, and the distance between components is large enough to allow for good airflow. For CWT's standards, the heatsinks are quite large on the primary side since there are no real heatsinks on the secondary side. There are several daughter boards to keep the main PCB as sparsely populated as possible; it would also need a larger PCB without these daughter boards.


The transient filter is in two parts, with a single X and two Y caps at the AC receptacle and the second part on the main PCB including all other components. The MOV is covered in heat-shrink tubing, so it will stay in place when dealing with a high power surge that partially or completely destroys it. You don't want parts flying around inside the PSU.


Large inrush currents are suppressed by an NTC thermistor and bypass relay combination.


The single bridge rectifier is bolted onto a beefy heatsink.


ON Semiconductor provides the APFC converter's FETs. The same goes for the boost diode. Finally, the bulk caps are provided by Teapo and have enough capacity to provide a hold-up time of over 17 ms. The significant let-down here is the 85 °C rating. This is probably a reason for the relatively short five-year warranty. That having been said, I believe that five years are quite enough for a power supply.


The APFC controller is the Champion CM6500UNX, and there is a FET that isolates the APFC converter while the PSU is in standby mode.


Two On Semiconductor FETs installed in a half-bridge topology are the main FETs.


The LLC resonant controller is a Champion U6901VAC.


The unit's main transformer is directly connected to the board that hosts the +12 V FETs.


The FETs that regulate the +12 V rail are six On Semiconductor NTMFS5C430Ns. They are installed on a vertical board close to the main transformer. Exactly the same number and type of FETs are used in the Corsair RM850x (2021).


Two DC-DC converters generate the minor rails. They use four UBIQ FETs, and the common PWM controller is a UPI Semi uP3861P. The same VRMs are also used in the Corsair RM850x (2021).


To keep the cost low, Teapo and Elite provide the electrolytic caps. I am not so fond of the Teapo SC caps because of their low lifetime. There are also 18 polymer caps by APAQ, which are much more tolerant to high operating temperatures.


The 5VSB circuit uses a PS1045L SBR on its secondary side, and the standby PWM controller is an On-Bright OB5282 IC. Once the PSU starts, the 5VSB rail takes power from the 5 V rail. This is done through a change-over switch, a Sync Power SPN3006 FET.


There are lots of polymer caps on the modular board's face.


Soldering quality is excellent.


The supervisor IC is a Weltrend WT7527RT. There is also an LM393G dual differential comparator, which is most likely used by the protection features circuit.


The cooling fan is a be quiet! BQ QF2-12025-MS. It has a diameter of 120 mm and uses a rifle bearing.