A Look Inside

Before reading this page we strongly suggest to take a look at this article, which will help you understand the internal components of a PSU much better.


Once we removed the top cover of the casing we were blown away. This is one of the cleanest PSU designs we have ever seen, mainly due to the very few cables that are used internally. Actually only one connector and the 5VSB go through cables to the modular PCB. Also all internal components (heatsinks, capacitors, coils etc.) are perfectly aligned and installed with high precision. We save the interesting design that this unit uses for last. Usually the primary side resides on one side and the secondary on the other. In this PSU the primary side is located on the front of the PSU and the secondary on the rear where the modular PCB is, so power has to travel a very small distance, thus energy losses are minimized. Very simple but clever thinking Enermax!


The AC receptacle includes an integrated line filter which contains two coils, 2Y and one X caps. Next to the line filter we have the main power switch which despite its small size can handle up to 16A at 250V. The transient filtering stage continues on the main PCB with three coils, an MOV, two Y and one X caps. As you can see the transient filter has way more than the required components.


The bridge rectifier is an LL25XB60 and uses a dedicated heatsink.


In the APFC we find four FQA24N50 mosfets and a boost diode. The smoothing/reservoir caps are three parallel Matsushita/Panasonic (330μF, 400V, 105°C). In front of them there is the heatsink that holds the primary switches, four MDF18N50 mosfets, which utilize a Phase-Shifted Full-Bridge topology.


On one of the two sides we find two vertical daughter-boards. The first, from the right, holds the APFC controller, an Infineon 2PCS02 IC and the second a Texas Instruments UCC28950 Phase-Shifted Full-Bridge controller.


The main transformer has increased wire density so its size is significant smaller compared to the ones used in similar capacity PSUs and on top of that it features increased heat dissipation thanks to its design. In front of the main transformer there is the secondary heatsink that holds all mosfets that regulate +12V. In total there are six IPP015N04N and there is space for additional two (maybe for the 1500W MaxRevo). Two toroidal chokes along with ten Rubycon caps (1500uF, 16V, 105°C, ZLK series) filter the +12V output (the chokes also take part in the regulation process since the unit does not use an LLC-resonant converter).


The +12V are fed to the modular PCB, which holds the 5V and 3.3V DC-DC converters, through eight copper bridges. This is why there no wires connecting the main PCB with the modular one. The two VRMs (Voltage Regulation Modules) use one APW7073A PWM controller and four APM2556N mosfets each. On the left resides the 5V VRM and on the opposite side the 3.3V one. Three polymer caps are used on each VRM to filter current ripple. On the front of the modular PCB we find the supervisor IC, a PS238 which supports six +12V channels OCP but no OTP.


The 5VSB are generated through a 10U60CT SBR, a small transformer and a Nippon Chemi-Con cap. The above SBR can give up to 10A and since it is bolted to a heatsink we wonder why Enermax kept 5VSB max power to only 4A.


Soldering quality on the main PCB is considerably better compared to other Enermax PSUs we have seen in the past, but it still is far behind Delta's and Seasonic's implementations. Also we found some long component leads, something that we consider very dangerous for the health of a PSU.


The cooling fan is an Enermax ED142512S-DA (139mm, 12V, 0.6A, 900 ~ 2000rpm) which uses twister ball bearing for increased lifespan and reduced noise output.