A Look Inside

The Design is based on a strong 12V PSU using the LLC resonance converter topology. 3.3 and 5V are generated from 12V using DC-DC converter. This topology is very common in modern PSU's.

Directly on the AC input there are two Y capacitors for burst pulse filtering. For the continued filtering the manufacturer placed an additional PCB, located between the Fan and the hot air exhaust, on the top side. Four Y, two X Caps one MOV, one CMR and a normal Choke are located on this PCB. On the main PCB there are two additional Y caps and a CMR choke. The rectification is done using two LL15XB60 (each 600V, 15A) on a small heatsink. The APFC uses three FCP22N60N Mosfets (600V, 22A, 0.165Ohm) and a SiC Diode. Three Rubycon (each 450V, 220uF, 105C) are used as APFC capacitors. The LLC Resonance converter is controlled by a CM6901. On the primary side there are four 20N60CFD (650V, 20.7A, 0.22 Ohm) Mosfets. In this PSU there are rather small heatsinks used in comparison to others.

The 12V rectification Mosfets are located on the bottom side of the PCB. Those are only cooled indirectly via the case. The case is strengthened with a metal Plate in the Mosfet area. On the secondary side extremely high end Nippon Chemi-Con and Rubycon capacitors are used for DC filtering. Because the non modular cables are connected directly to the main PCB, 3.3 and 5V must also be conducted on the main PCB. Doing this takes a lot of valuable space of the secondary side. Even the 3.3 and 5V converters are not located as usual on the back end PCB but on a daughter PCB just in middle of the secondary side. This makes the design a mess. There is not enough space for big heatsinks and the entire AC filtering on the main PCB. Overall there are too many components, which block the airflow and make this PSU rather inefficient from a cooling perspective, and that results in a 2400RPM+ fan for a 850 Watt PSU ...

---

Page 1 - Introduction

Page 2 - Preview

Page 3 - Delivery / Specs

Page 4 - A Look Inside

Page 5 - Input/Output Power and Efficiency

Page 6 - Result Analysis and Discussion

Page 7 - Conclusion