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Enermax Digifanless 550W Power Supply Review

A Look Inside And Component Analysis

Our main tools for disassembling PSUs are a Thermaltronics soldering and rework station and a Hakko 808 desoldering gun.

Parts Description

Primary Side
Transient Filter2x Y caps, 1x X cap, 2x CM chokes, 1x MOV
Inrush ProtectionNTC Thermistor & Relay
Bridge Rectifier(s)2x Shindengen LL25XB60
APFC MOSFETs2x Toshiba K20J60U MOSFETs
APFC Boost Diode1x CREE C3D08060A
Hold-up Cap(s)1x Nippon Chemi-Con (400V, 470uF, 105 °C, KMQ)
Main Switchers2x Toshiba K20J60U MOSFETs
Digital ControllerMicrochip PIC32MX230F064D
EEPROMMicrochip 24LC02B
APFC ControllerChampion CM6502TX, CM03X Green PFC controller
LLC ControllerChampion CM6901X
TopologyPrimary side: LLC Resonant Converter Secondary side: Synchronous Rectification & DC-DC converters
Secondary Side
+12V MOSFETsUnknown number of MOSFETs
5V & 3.3VDC-DC Converters: 8x Sinopower SM3116NA MOSFETs
2x APW7073 PWM Controllers
Filtering CapacitorsElectrolytics: Nippon Chemi-Con (105°C, KZE)
Polymers: Duratech, Enesol

5VSB Circuit
Standby PWM ControllerPower Integrations TOP265EG

It is nice to see Enermax release a fresh semi-digital platform. We describe it as semi-digital because the digital circuit controls only the +12V rail. The other sections of this unit (APFC, main switchers, 5VSB circuit and the minor rails) are controlled by classic analog components. We would like to see the digital circuit controlling more sections; however, we suspect that Enermax wanted to mix the already tested and reliable analog technology with the digital in order to minimize problems in the long run. On the primary side of the EDF550AWN, we find an LLC resonant converter, while on the secondary side two DC-DC converters generate the minor rails. The +12V rail is generated by a series of MOSFETs, which are handled by a Microchip 32-bit RISC CPU.

A small PCB holds the AC receptacle and the on/off switch along with one X and two Y caps. The EMI filter continues on the mainboard with two CM chokes and an MOV (metal-oxide varistor). Normally, this filter should have an additional X cap and another pair of Y caps. For protection against large inrush currents, Enermax used an NTC thermistor along with an electromagnetic relay, which allows it to cool down and at the same time provides a small efficiency boost.

A pair of bridge rectifiers are provided by Shindengen (model number LL25XB60); both are bolted on the heat sinks and they are very strong for this unit’s capacity.

In the APFC converter, we find not one, but two PFC input capacitors, which filter the high-frequency ripple of the fully rectified AC signal. Two MOSFETs (2x Toshiba K20J60U) along with a single CREE C3D08060A boost diode shape the current's waveform in the APFC. A single Chemi-Con (400V, 470uF, 105-degree Celsius, KMQ) is used as a smoothing/reservoir cap; its capacity is adequate for the needs of this PSU.

The APFC converter controls include a Champion CM6502TX and a CM03X Green PFC controller, used to further decrease energy loss. Both of the controllers are installed on a small daughterboard.

The main switchers are a couple of Toshiba K20J60U MOSFETs, the same that the APFC converter uses. In the control section of the LLC resonant converter, there is a Champion CM6901TX IC, which is installed on the solder side of the main PCB.

On the secondary side, we had to remove the modular board, which attaches to the main PCB through four small screws, in order to get a clear view of the components. The +12V rail includes several MOSFETs that are installed on a vertical PCB. The vertical PCB is cooled by a mix of large heat sinks, which compensate for the lack of active cooling (a fan). We didn't want to dismantle the PSU further, so we stopped at the heat sinks. All capacitors in this section of the PCB are electrolytics provided by Chemi-Con, so they are of high quality. In a passive PSU with increased internal temperatures, Japanese electrolytic caps are the only way to go; lower-quality caps would compromise the unit's reliability and decrease its lifetime.

Both DC-DC converters are installed directly on the modular PCB in an effort to decrease energy loss. Two Anpec APW7073 controllers handle eight Sinopower SM3116NA MOSFETs, which deliver the minor rails. We also found a SITI PS113 IC on the solder side of the modular board, which is a secondary monitoring IC, offering some of the PSU's protection features (like over-voltage and under-voltage protection). 

On the front side of the modular PCB, several polymer caps from Enesol and Duratech filter the rails. These caps, although not Japanese, are still of high quality.

The standby off-line switcher that generates the 5VSB rail is a Power Integrations TOP265EG model. It incorporates a MOSFET along with other components to deliver up to 26W of power, even with 50 degrees C ambient. With 230VAC input, this IC can deliver up to 40W.

The solder quality is good, and at the level expected from a high-end PSU. If you look closely at the photos above, you'll notice that the name of the worker who inspected the PCB is printed on it. Enermax does this on all of its PSUs, possibly to identify the right person in case something goes wrong. In any case, we think it's pretty cool.

The digital controller is a 32-bit RISC CPU clocked at 40MHz, provided by Microchip (model number PIC32MX230F064D, supported by 24LC02B EEPROM) and installed on a modular board located on the PSU's secondary side.

Zero Delay Power Monitoring System

Since this PSU utilizes a digital interface, it is able to connect to the system's mainboard through a USB interface in order to transmit data and receive commands. Enermax's ZDPMS software allows users to monitor the PSU's operation and customize some important functions, including switching between multi or single +12V rail mode, fine-tuning +12V output voltage levels and setting the OCP/OVP trigger points. You can download the software from the product's webpage.

The first thing you will see once you start the ZDPMS program is its welcome screen, which stays on for about five seconds but can be disabled by clicking the Don't Remind Me option. Once you enter the main program, you see an intuitive and easy-to-follow interface. The software's manual provides a nice screenshot of the program's main control window, explaining the interface.

In the Additional Information tab, you will find the Usage button, which allows the tracking of the operation time from the moment the ZDPMS software is started. By entering what your local utility charges, you can estimate the PSU's electricity cost. In addition to usage information, the control/monitor program will show a warning if something goes wrong. The most important one to watch out for is the Over Temperature message, which pops up once the PSU's internal temperature exceeds 80 degrees C. According to Enermax, once it hits roughly 90 to 120 degrees C, the over-temperature protection kicks in and shuts the PSU down to save it from breaking. The other two warning messages have to do with over-current and over-voltage protection, and they pop up if the output current/voltage readings reach the preset warning points.

Another interesting feature of the ZDPMS software is Simple Mode, which can be enabled by clicking the middle button on the Window Control tab. This mode provides only the essential information like total output, efficiency and temperature data. To return to the normal window, just click the Simple Mode window twice.

The ZDPMS may lack a fancy interface, but it is easy to follow and it won't confuse anyone (even inexperienced users). It provides all the necessary functionality, and throughout our long test sessions, we found it to be reliable. Communication with the program was lost only when we removed the AC input from the PSU, which was expected; once we restored power, the communication link was up again and the program worked perfectly without needing to restart.

  • blackmagnum
    If you think buying a mid-range PSU that costs as much as an enthusiast gaming CPU or graphics card, then you have more money than sense.
    Reply
  • PaulBags
    Why'd my commented get deleted? "This is a passively-cooled PSU, so you should install it with the top exhaust grille facing downward." is totally wrong advice, if you don't believe me read the warnings in the picture YOU took.
    Reply
  • Calculatron
    Ironically, I have yet to try an Enermax PSU, although I really like their other products; I have an ETS-T40-TB, a whole myriad of their fans, and the Ostrog Pink case.
    Reply
  • uglyduckling81
    "This is a passively-cooled PSU, so you should install it with the top exhaust grille facing downward. If you don’t follow this advice, hot air will be trapped inside the PSU"

    Hot air rises. If you have the opening facing down you will be trapping hot air inside. Read your own comment "top exhaust". 'Top' means on top, 'exhaust' means expulsion of air not intake.
    The PSU clearly has vents on the back and sides so I think it's a moot point either way but it's clearly a better idea to install it with the top opening facing upwards.
    Reply
  • nukemaster
    15875927 said:
    Why'd my commented get deleted? "This is a passively-cooled PSU, so you should install it with the top exhaust grille facing downward." is totally wrong advice, if you don't believe me read the warnings in the picture YOU took.
    I think your post got lost(forum bug maybe), not removed. I would see if it was removed and it was not.

    I think this would depend on the case you are using to be honest.

    System air will cool it.

    If the power supply is at the top of your system putting its vent up will cause heat to have no place to go in many cases. Power supplies in the bottom of the case would be better served with the power supply vent face up.

    The power supply has software to let you see the temperatures anyway so you can test. Tom's tests in a hotbox so it is not an actual case.
    http://www.tomshardware.com/reviews/how-we-test-psu,4042.html
    Reply
  • Aris_Mp
    guys sorry for this mistake. It is with the fan grill facing upwards and not down. This is how a single word can bring doom!
    Reply
  • Blueberries
    These are solid! I'd take a SeaSonic SS-520FL2 for $140 over this any day, though!
    Reply
  • PaulBags
    These are solid! I'd take a SeaSonic SS-520FL2 for $140 over this any day, though!
    I have the seasonic, I love it. I prefer the modular connector layout on it too, this emermax only offers a few oddly placed plugs by comparison. The cables arn't as good though, and you don't even get enough to populate all the plugs, although it's sufficent for most scenarios for a 520w PSU.

    I'd very much like to see AC cable clips become standard, I've had the ac work loose on me before when I turned a case slightly to plug something in, glad I didn't have anything important up at the time.


    To anyone who _would_ want the enermax over the seasonic I'm genuinely curious as to why. It's always good to learn and/or gain perspective.
    Reply
  • eklipz330
    i just realized my 7 year warranty for my corsair hx750 expires this year QQ
    Reply
  • f-14
    15875927 said:
    Why'd my commented get deleted? "This is a passively-cooled PSU, so you should install it with the top exhaust grille facing downward." is totally wrong advice, if you don't believe me read the warnings in the picture YOU took.
    I think your post got lost(forum bug maybe), not removed. I would see if it was removed and it was not.

    I think this would depend on the case you are using to be honest.

    System air will cool it.

    If the power supply is at the top of your system putting its vent up will cause heat to have no place to go in many cases. Power supplies in the bottom of the case would be better served with the power supply vent face up.

    The power supply has software to let you see the temperatures anyway so you can test. Tom's tests in a hotbox so it is not an actual case.
    http://www.tomshardware.com/reviews/how-we-test-psu,4042.html

    page 2 second set of pictures picture number 5 what does it specifically say? where does hotair go, where does cold air go, in a fanless case your argument is excellent advice on how to waste money and start a fire. if you are running an antec 1200 with all the fans unless this psu is mounted at the top with the vents down and all the other fans are set to intake into the case you are in great shape, however that mitigates the point of having a fanless psu, you go fanless because you don't want there to be any noise, much less a hoover vacuum for a case.

    i haven't read the warranty card, but i am sure it says something about keeping the psu vents facing up when mounted at the bottom of the case, when mounted on the side that would be interesting.

    nice psu, i will keep it in mind for the next time a customer wants a zero or low noise build.

    someday there will be a liquid cooled PSU, i laugh because of water conduction electricity, but where there is a will, there is a way to circumvent conductivity and deal with all that heat i am sure.
    Reply