Enermax Platimax 1200 W

Enermax Platimax 1200 W

Voltage Regulation & Efficiency »

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.


The manufacturer of the PSU is Enermax itself. The two higher capacity Platimax units are based on an updated version of the platform used in the MaxRevo series PSUs. Currently this platform is among the most innovative due to its design and enjoys a high level of workmanship and top notch components. The topology used in the primary section is the Phase-Shifted Full-Bridge, which is one of the most expensive to implement, since it needs four primary mosfets. It provides lossless switching, greatly increasing efficiency.


The AC receptacle incorporates a complete line filter made by Yunpen (Y015T1). The latter consists of two Y and one X caps and a CM choke. Since a two layer EMI filter is demanded in a desktop PSU, on the main PCB we find additional transient filtering components; namely three CM chokes, two Y and one X caps and an MOV (Metal Oxide Varistor). The last component provides protection against spikes coming from the power grid so it is essential in every PSU.


The bridge rectifier is provided by the Japanese company Shindengen and its model number is LL25XB60. It can handle up to 25A of current so it will easily cope with the unit's capacity. It is bolted on a leaning heatsink and we take this as a (small) design fault that passed below the quality control radar. In such a high price/quality PSU we won't leave anything uncommented.


In the APFC four Toshiba K20J60T mosfets and the necessary boost diode shape the current waveform. The three parallel hold up caps are provided by Matsushita/Panasonic (330µF each or 990µF combined, 400V, 105°C). Finally the PFC controller, an Infineon ICE2PCS02, is mounted on a vertical daughter-board. On the same PCB an LM393 voltage comparator is also housed, providing assistance in overvoltage and undervoltage protection.


The four, MDF18N50, primary fets are arranged in a Phase-Shifted Full-Bridge topology to minimize energy losses thus boost efficiency. Their PWM controller is a UCC28950 IC which is soldered on the second daughter-board. On the latter we also find a UCC27324, a high speed low-side power mosfet driver. The main transformer utilizes a special design and has high density, so it can handle extreme power and at the same time it provides excellent heat dissipation.


The 5VSB rail is rectified by an SBR10U60, which can handle up to 10A but in this case it has to deal with only 3A max. This SBR isn't installed on a heatsink, which makes it more efficient. As a diode's operating temperature increases, so does its voltage drop. Once some current passes through it, it is decreased. To be more specific the SBR10U60CT with 5A passing through has 0.48V voltage drop at 25ºC and 0.42V at 125ºC. The standby PWM controller is a TOPSwitch-JX TOP265 which is bolted on a dedicated heatsink.


In the secondary side synchronous design is used of course and the +12V rails are generated by eight IPP041?04? mosfets. In front of the secondary heatsink there are two toroidal chokes which take part in the filtering/rectifying process of +12V. Between the chokes and the modular PCB we find an array of ten Rubycon filtering caps (1500uF, 16V, 105°C, ZLK series).


The VRMs that generate the minor rails are located on the solder side of the modular PCB, for decreased energy losses; since the rails are transferred right away to the modular sockets without having to travel long distance though wires and PCB traces. Regardless how thick a wire or a trace is, it still has voltage drops especially when lots of current passes through it. At each VRM a APW7073A PWM controller along with four APM2556N are used.


On the front of the modular PCB the supervisor IC is installed. This is a SITI PS238 which supports OCP for up to six +12V rails, so it matches the number of +12V rails this PSU has. On the lower end of the modular PCB we can see the thick copper bush bars that transfer +12V. This is the copper-bridge transmission array that Enermax mentions in their list of PSU features.


Soldering quality is quite good, especially if we compare it to older Enermax implementations, but it still cannot compete with Delta or Seasonic high-end units. Nevertheless it left us quite satisfied.


The cooling fan has Enermax's logo on it and its model number is ED142512S-DA (139mm, 12V, 0.6A, 900 ~ 2000rpm). It features twister bearings for increased lifespan and at low RPM you can characterize it as quiet.
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