A Look Inside & Component Analysis

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


The OEM of this unit is High Power/Sirtec, and the platform utilizes a very modern and efficient design for a mere Silver PSU. The primary side uses an LLC resonant converter to boost efficiency, something that we see for the first time in a Silver efficiency unit, and the secondary side uses DC-DC converters to generate the minor rails. We are pretty sure that this platform could clear out Gold levels with a little tuning and wonder why Silverstone didn't take that route.


As usual, the transient filtering stage starts at the AC receptacle with two Y caps and a single X cap. A CM02X is mounted on the latter. This IC blocks current through the X cap discharge resistor when AC voltage is connected and automatically discharges the aforementioned cap through the discharge resistor when AC is disconnected. This leads to higher efficiency since X caps tend to keep their charge for quite a long time once AC power is cut off, which is why bleeding resistors are used as a safety precaution. However, some energy is lost on such resistors while the PSU is operating, something that the CM02X takes care of by cutting the bleeding resistor off the circuit. The second part of the transient filtering stage is located on the main PCB and consists of two small CM chokes, a single X cap, and a pair of Y caps. There is also an MOV (Metal Oxide Varistor).


The bridge rectifiers are two parallel GBU805 that can rectify up to 16A of current together.


The boost diode in the APFC circuit is an LQA 08TC600 and two Infineon SPP20N60C3 fets are used along with it. The hold-up cap is provided by Matsushita/Panasonic (400V, 390μF, 85°C) and looks rather small for the capacity of this unit. The PFC controller is a Champion CM6502S IC. It offers increased efficiency compared to the commonly used CM6800 and CM6802 combo of PFC/PWM controllers. Like the LLC resonant converter, we didn't expect to find such a high-efficiency PFC controller in a Silver efficiency PSU.


Two SPP20N60C3 fets are used as main switchers. The second photo shows the inductive and capacitive parts of the LLC resonant converter. The LLC resonant controller is a CM6901X IC.


The secondary side uses synchronous rectification. Four Infineon IPP034NE7N3 fets rectify the +12V rail, while the minor rails are generated by two DC-DC converters that are housed on the same PCB. Each DC-DC converter uses four IPD060N03L fets. The PWM controller is common for both VRMs.


All electrolytic caps of the secondary side are provided by Teapo and are rated at up to 105°C. We find several Teapo polymer caps on the VRMs.


The supervisor IC is a SITI PS224. It supports OCP for up to two +12V rails.


The standby PWM controller is a Power Integrations TNY278PN IC.


Four Teapo caps at the front of the PCB provide some extra ripple filtering to the rails, while a plastic shield on the rear protects the PCB from shorts.


Soldering quality on the main PCB is decent, but some component leads need a little more trimming.


The cooling fan is provided by Globe Fan and its model number is B1202512L (120 mm , 6.0 ~ 13.8 V, 0.18 A, 2000 RPM , 90.92 CFM, 34.0 dBA). It is equipped with double ball bearings for increased longevity (approximately 70,000 hours) and is not that quiet at full speed.