À l'intérieur
The first hint for a high Quality PSU can be seen when
taking a first look at its chassis. With this product you get a nice design and
a high quality case.
XFX decided to not follow Seasonic's design this time regarding the fan and went for a
Protechnic Electric 135mm Fan instead.
Right at the Input there is a YO15T1 (250V, 15A, CX = 0.1uF, CY= 3300pF*2,
Commom Mode (CM choke) = 2*0.3uH) from Yunpen Electronic.
At the PCB the transient filtering stage continues with two X, four Y, a CM amd
DM choke and four MOV (Metal-Oxid-Varistor).
Aditionally there is a NTC Tremistor for inrush curent limitation. A mechanical
relais shorts the NTC Termistor for normal operation.
The transient filtering stage is well done. We have not seen many PSUs with such
extensive input filtering.
Two GBJ 2506 (25A) are used for rectification. The PFC Booster consists of two
IPW60R099CP Mosfets (650V, 0.1Ohm, 31A) and one C3D101060 (600V, 10A, Qc 25nC) SiC
Schottky Diode. The APFC is controled by a
NCP1654
(54B65) from ON Semiconductor. The NCP1654 has a gate driver performance of
1.5A. This PSU has three APFC capacitors from Nippon Chemi-Con (KMR series;
330uF, 420V, 105C each). Four 60R160C6 (650V, 0.16Ohm, 23.8 A) Mosfets are used
on the primary side of the LLC resonance converter, which is controled by a
CM6901. The primary side of this PSU is rock solid. Especially the costly
transient filtering stage and the high end japanese Nippon Chemi-Con Capacitors
are excellent.
On the secondary side
eight BSC018N04LS (40V, 1.8mOhm, 100A) Mosfets do the 12V rectification. Those
Mosfets are high quality. However the design is basically the same as on XFX's
ProSeries and Seasonic X-Series PSU's with lower wattage rating. It seems to us,
that the design has been developed for a PSU in the 850W area and is now being
upscaled, mainly by the use of better components. In our view this design is to
close to the limit of a hardware breakdown. Especially the area between the
transformer connection and the first Mosfet is weak. XFX/Seasonic did also not
strengthen this area with an additional copper plate. This has the issue of a
relatively high electrical and thermal resistance, which results in a high
temperature of the Mosfets (especially the one closest to the transformer) at
high loads. The Mosfets are additionaly cooled with a thermal pad, that has been
connected to the case, which also gets very warm under high load at the area of
the Mosfets. In this PSU the +12V is the middle connection and also phisically
in the middle, the Mosfets are switching the ground.
We are also not so happy with the 12V distribution after
the rectification. The connection to the front PCB with the 3.3 and 5V
converters and the connectors is relatively weak. A PS232 is used for the
surveillance of the four 12V rails. Those 4 rails are generated with four coils.
There is even a fifth coil for the 3.3 and 5V converter supply. What we highly
like to see is that the manufacturer makes heavy use of high end japanese Nippon
Chemi-Con copacitors on the secondary side. In fact all capacitors we see are
from Nippon Chemi-Con with a 105°C rating. Extremely high end. Thank you
XFX/Seasonic!