Page 3 - Physical Look - Inside
As we usually do, we opened up the SilverStone SFX SX650-G 650W power supply to take a closer look at what is going on inside. Opening up this power supply will void your three year warranty, as the warranty seal covers one of the screws. For your benefit, we voided our warranty on this unit, so you do not need to. There are zero user serviceable parts inside anyway. Removing the top shell from the SFX SX650-G 650W is pretty easy, as we just remove the four screws at the top. However, to get a better look, you may have to unscrew a few more areas around the power supply. The OEM for the SilverStone SFX SX650-G 650W is High Power Electronic Co., Ltd/Sirfa. This OEM generally produces good power supplies, though they do not command the greatest of reputation compared to other OEMs like Seasonic or Super Flower. The photo above shows an overhead view of its internal components. Build quality is pretty good, even with a few patches of glue globs. Otherwise, there are many heatsinks found here left in a black finish.
The transient filter stage is the first input stage of any computer power supply, so we will take a closer look at this first. From here, there are several ferrite coils and one metal oxide varistor. A single X-capacitor and two Y-capacitors are placed at the AC receptacle, while another additional set of one X- and two Y-capacitors are found on the main board. In total, this is more than twice the amount of X and Y capacitors recommended, which is great to see. In addition, the MOV being present here is good, as they are intended to protect your power supply from AC line voltage spikes. A CMD02X IC also exists here to prevent current flow when AC is disconnected.
On the primary side, there is one Rubycon capacitor. It is rated at 470uF at 420V. It has a temperature rating of 85c. It is great to see Japanese-made capacitors here, as some cheaper units have capacitors made from Taiwan or China. On the other hand, I would have wished Sirfa put a higher 105c temperature rating capacitor here, as they generally boast a longer lifetime. In addition, an A6069H current mode control PWM regulator IC can be found under the main capacitor.
The power supply uses two unidentifiable rectifying bridges attached to each other. Once again, the space constraints make inspecting this power supply quite difficult. The active PFC circuit in the SilverStone SFX SX650-G 650W is controlled by an Infineon ICE3PCS01 chip. Other components in the active PFC circuitry were pretty difficult to get a closer look at, especially with how small this whole package is. Further research reveals there are four Toshiba K16A60W power transistors. These handle both the PFC circuitry as well as the switching duties, with two for each. A Champion CM6901X PFC as the PWM controller. Each K16A60W transistor is rated to deliver 15.8A at 100 degrees Celsius continuously, at a maximum resistance of 0.19 ohms. This on characteristic is called Static Drain-Source On-Resistance or commonly abbreviated as RDS(on). The more efficient the component is, the lower the RDS(on) value, since it wastes less power with lower resistance.
As for the secondary side, there are quite a few more Japanese capacitors, including both the electrolytic and polymer capacitors. As with modern high efficiency power supplies, all rectifiers produce the +12V out -- while the +5V and +3.3V outputs are generated from the +12V output using a DC to DC converter within the power supply unit. An ANPEC APW7159 synchronous buck PWM controller can be spotted in this stage. The +12V output is regulated by six Toshiba TPHR8504PL chips cooled by the chassis. Drain source voltage is rated at 40V, with a continuous drain current of 150A at 25c. An RDS(on) value of 0.001 ohm maximum and 0.0014 ohm typical are provided. The +5V and +3.3V rails are powered by components on a daughterboard, which were found be controlled by six Infineon BSC0906NS. Finally, a Silicon Touch PS224 IC provides over current protection, over/under voltage protection, and power good signal generation. The datasheets for all components mentioned in this review can be found on their respective manufacturer's websites.
At the back, we have a large daughterboard covering the entire rear panel. This is where the modular cable sockets go. Layout of the output connectors can be found on the previous page. SilverStone and Sirfa has done a good job in ensuring quality is not sacrificed here. Soldering is quite good overall, which is pretty important for a smaller power supply like this one. Component selection too is good with a decent layout for cooling. In addition, with the number of heatsinks in this unit, I doubt cooling will be an issue.
Speaking of cooling, the last component to look at is an important one, as it draws in air to let all these small components breathe easy. This is the 92mm Globe Fan connected to the mainboard of the power supply. Further research of the S0921512HB does not reveal a whole lot more about this fan, besides the fact it operates at 12V and 0.45A with fluid dynamic bearings for quieter operation. Overall quality of the fan is thus a bit of an unknown, but it should last at least the length of the warranty period.
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion