A Look Inside And Component Analysis
Our main tools for the disassembly of each PSU we examine are a Thermaltronics soldering and rework station along with a Hakko 808 de-soldering gun.
|Transient Filter||4x Y caps, 2x X caps, 2x CM chokes, 1x MOV, NTC Thermistor|
|Bridge Rectifier(s)||1x Vishary BU1506|
|APFC MOSFETs||2x IPP50R140CP|
|APFC Boost Diode||1x CREE c3D07060|
|Hold-Up Cap(s)||1x Nippon Chemi-Con (450V, 330uF, 105 °C, (221 °F) KMR series)|
|Main Switchers||2x IPP50R140CP|
|APFC Controller||Champion CM6500|
|Switching Controller||Champion CM6901|
|Efficiency Boost||LLC Resonant Converter|
|+12V MOSFETs||6x International Rectifier IRFH7004PbF|
|5V / 3.3V||DC-DC Converters: 2x 86350D MOSFETs PWM Controller: 2x APW7073|
|Filtering Capacitors||Electrolytics Chemi-Con: 105 °C (221 °F), KY series Suncon: 105 °C (221 °F) Taicon: 105 °C (221 °F) Su'scon: 105 °C (221 °F) Teapo: 105 °C (221 °F) Polymers: Gemcon, G-LUXON|
|Supervisor IC||SITI PS223|
|Fan Model||ADDA AD0812UBB-D91 (12V, 0.36A)|
The PCB is small and densely populated, so we had to remove the primary and secondary heat sinks along with the bulk capacitor in order to identify the parts inside. The OEM is Enhance, a company that specializes in manufacturing SFX-based PSUs. On the primary side, we find an LLC converter for increased efficiency, while synchronous rectification is used in the secondary side, along with two small DC-DC converters, for generating the minor rails. Contrary to the ST45SF-G that exclusively used Japanese caps, this one uses a mix of Japanese and Taiwanese ones. It's definitely not the best bundle of capacitors, especially for a PSU that costs $140.
A thermal pad is used for cooling the MOSFETs (metal-oxide-semiconductor field-effect transistors) that generate the +12V rail, transferring heat through the chassis. In the photo above, you can see the pad isn't aligned properly, so the last of the MOSFETs wasn't fully covered by it.
The transient/EMI filter starts right at the AC receptacle with two Y caps and a single X cap. There is also a CM choke on the small PCB, along with a fuse. On the main PCB we find the rest of the filter's components, including two Y caps and one X cap, a CM choke and an MOV (metal oxide varistor).
The single bridge rectifier is bolted onto the same heat sink with the main switchers. It is provided by Vishay, and its model number is BU1506. That part can handle up to 15A of current, making it overkill for this PSU.
The APFC (Active Power Factor Correction) converter uses two Infineon IPP50R140CP FETa, along with a CREE C3D08060A boost diode. The bulk cap is by Nippon Chemi-Con (450V, 330uF, 105C, KMR series) and its capacity looks low for the needs of this unit. Our hold-up tests will shed more light on this matter. Its voltage rating is significantly higher than the voltage of the APFC's DC bus (approximately 380 VDC). This is great, of course. Usually manufacturers tend to use lower voltage rating caps to save some bucks.
As we already stated, the main switchers reside on the same heat sink along with the bridge rectifier. They are a couple of Infineon IPP50R140CP FETs.
The daughter board houses the LLC resonant controller, a Champion CM6901 IC. This controller operates the main switchers at PWM mode with light loads and switches to FM mode when demands increase.
On a quite large, vertical daughter board located on the secondary side, we find the APFC controller, a Champion CM6500 IC, and the supervisor IC, which is a SITI PS223. Since this is among the few controllers supporting Over-Temperature Protection (OTP), we find it strange that this functionality isn't exposed (at least according to SilverStone's specifications). Also, the PS223 supports Over-Current Protection (OCP) for up to two +12V rails. However, according to the official specifications, again there is only one in this unit.
The six FETs that generate the +12V rail are installed on the solder side of the main PCB. They are provided by International Rectifier, and their model number is IRFH7004PbF.
Two DC-DC converters generate the minor rails. On each of them an Anpec APW7073 PWM controller is used along with a single FET (86350D). Unfortunately, both DC-DC converters, along with the rest of the components in the secondary side, aren't properly cooled by the small fan located on top of the primary side, mostly because of the AC receptacle PCB that occupies significant space. This might affect the PSU's performance under tough conditions, and in the long run it could affect reliability, too.
Enhance does something really strange here. It's possible the company was out of Japanese capacitors, so it used a mix of Japanese (Chemi-Con) and Taiwanese (Taicon, Teapo and Su'scon) electrolytic caps on the PSU's mainboard. We don't have a problem with Taicon and Teapo, but we believe that they should use something better than Su'scon.
At the front of the modular board are high-quality Suncon electrolytic capacitors, providing some extra ripple filtering.
Soldering quality is good, but definitely not the best we have seen from Enhance. Right between the primary and secondary sides sits a Silicon Labs Si8230BD isolated driver.
Several shunt resistors are used to provide data to the OCP circuit of the PS223 supervisor IC. Two of them are for the minor rails and the rest for +12V. However, this PSU has only one +12V rail.
The fan is by ADDA, a respected manufacturer, and it uses ball bearings for increased life. Its model number is AD0812UB-D91 (12V, 0.36A). The fan is a true speed demon; with 12V we measured around 5000 RPM. Thankfully, even under the worst conditions it won't spin that fast. But it will still be noisy once the PSU's internals get hot.