Page 3 - Physical Look - Inside
As we usually do, we opened up the SilverStone SX800-LTI 800W 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 chassis 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 SilverStone SX800-LTI 800W is not as easy as I would have expected. Normally we would remove the four screws, with one on each corner of the side. However, I also had to remove the metal grille above to dislodge the shell from the fan inside. Even so, this extra step is not too bad. The OEM for the SilverStone SX800-LTI 800W is Enhance Electronics. While we have not seen this power supply before, other reviews have said this is the same platform as the Lian Li PE-750 750W. The photo above shows an overhead view of its internal components. Build quality looks acceptable, despite several patches of glue globs. Enhance generally has a good reputation for power supplies, so we will see how this affects the build quality. Otherwise, there is one large heatsink found here left in a natural silver 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 two ferrite coils and one metal oxide varistor. Two X-capacitors can be found here at the AC receptacle in addition to two Y-capacitors. A single X and two more Y-capacitors can be found near the area, making for more than twice the amount of X and Y capacitors than recommended. In addition, the MOV being present here is good, as they are intended to protect your power supply from AC line voltage spikes. An NTC thermistor and relay can also be found here to reduce inrush currents. A Sanken A6069H current mode control PWM regulator IC for controlling standby power can be spotted as well.
On the primary side there are two Rubycon capacitors. They are rated at 270uF 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 am surprised they are rated at a lower 85c temperature. Generally, more expensive power supplies have their main hold-up capacitors rated at 105c, as they generally boast a longer lifetime.
The power supply uses one GBU15L06 rectifying bridge attached to a heatsink, supporting up to 15A of current at 115c. At 115V, the theoretical power you can pull from the bridge rectifier is 1725W at 100% efficiency. Of course, this is purely from the bridge rectifier, and not all components in the power supply can actually hold this workload. Even so, this is well above the necessary requirements for an 800W power supply. The active PFC circuit in the SilverStone SX800-LTI 800W is controlled by a Champion 6502TX and a CM03X Green PFC chip. Otherwise, other components in the active PFC circuitry were hard to get a closer look at, due to the pure compactness of the SFX-L power supply. However, further research shows both the two main switchers are Infineon IPP50R140CPs, driven by a Silicon Labs Si8230BD. This transistor is rated to deliver 15A at 100 degrees Celsius continuously, with a maximum resistance of 0.14 ohm and a typical resistance of 0.13 ohm. 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. A single CREE C3D10060A Schottky boost diode is also found in the active PFC circuit.
As for the secondary side, there are quite a few more Japanese capacitors made from Rubycon and Nippon Chemi-Con, including both the electrolytic and polymer capacitors. The electrolytic capacitors are all rated at least 105c. 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. The +12V output is regulated by eight Infineon BCS014N04LS MOSFETs, cooled by the chassis. They are unlike most typical MOSFETs, as they have eight pins instead of the typical three. Drain source voltage is rated at 40V, with a continuous drain current of 100A at 25c. An RDS(on) value of 0.0014 ohm maximum and 0.0011 ohm typical are provided. The +5V and +3.3V rails are powered by components on two daughterboards, with each one holding two Infineon BSC018NE2LS DC to DC converters, and controlled by an ANPEC APW7073. Finally, a Silicon Touch PS223 protection IC can be found, to provide over-voltage, under-voltage, over-current, short-circuit, and over-temperature protection. 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 hidden by a large plastic shield to prevent any contact between the components on the daughterboard and the rest of the power supply. It is also where the modular cable sockets go. Layout of the output connectors can be found on the previous page. The compactness of the SilverStone SX800-LTI 800W is one of the main reasons why this unit is a lot harder to build or inspect, but I have to say SilverStone and Enhance have done a good job in ensuring quality is not sacrificed here. Soldering is pretty good, which is even more crucial on a smaller board like this. Component selection too is pretty great, despite the lower rated main capacitors, with decent layout for cooling. Obviously, with a form factor like the SFX-L size, cooling is even more important.
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 a Globe Fan S1201512HB 120mm fan connected to the mainboard of the power supply. It should be noted this is a semi-passive power supply, as the fan only kicks in at higher loads. Further research of the Globe Fan S1201512HB proved fruitless, as not a whole lot of information can be found on these fans. It operates at 12V and 0.45A, offering sleeve bearings for quieter operation.
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion