NZXT C650 650W Report (Page 3 of 4)

Page 3 - Physical Look - Inside

In order to further investigate the design details of the NZXT C650 650W power supply unit, some panel removal is required. It is important to note two important concerns before disassembling any power supply unit. First, certain components, such as the capacitors, may cause an electrical shock if not discharged properly. Second, your ten-year warranty will be voided if the screws on the power supply unit are removed. Therefore, unnecessary disassembling of a power supply unit should be avoided. Once the top panel of the C650 is removed, a closer look of the electronic components can be revealed. The OEM for the power supply is Seasonic, which means excellent quality in my opinion.

Let us first take a look at the transient filter stage of the power supply unit. The function of the transient filter stage is to protect the computer from the power grid noise and voltage spikes. In the NZXT C650 650W power supply unit, the transient filter stage contains two X-capacitors, four Y-capacitors, two common mode chokes, and one metal oxide varistor. The MOV here is to prevent the computer from being damaged by lightning surges. It is worth mentioning not all the power supply units in the market have an MOV. There are two sets of X-capacitors and Y-capacitors, with one set on the PCB board behind the power plug and the other set found on the main PCB board.

Now, we move on to the primary side. The one big capacitor in the photo is from Hitachi, which is rated at 470uF at 400V. The temperature is rated at 105c, which is the standard in terms of durability. This one is a Japanese-made capacitor, which costs more than those made in other places like China, but the quality is better. For the standby PWM control, there is a Excelliance MOS EM8569. By the left-hand side of the transformer in the photo, there is a pair of heatsink panels. On each heatsink panel, two Greatpower GPT10N50AD power MOSFET transistors are used as the main switchers. The GPT10N50AD can delivery power up to 9.7A continuously and a maximum drain-source on-resistance of 0.7ohms according to the datasheet. Note the lower the drain-source on-resistance, the more efficient the transistor will be.

In the above photo, we can see there is another heatsink right below the pair of MOSFET heatsink panels. There are two rectifying bridges attached to that heatsink. From what I can see, the rectifying bridge is a GBU1006. At 115V, the maximum rectified forward current capacity with heatsink is 10A, so you can theoretically pull up to 2300W (2 * 10A * 115V) from the bridge rectifier at 100% efficiency -- of course, this is limited by the fact that it is not 100% efficient and also neglects the fact that not every component in the system are able to keep up. On the left side of the transformer, there is a large heatsink, where you can find a pair of Infineon IPA60R180P7S as the APFC MOSFETs. The Infineon IPA60R180P7S can support 11A at 100c. There is also a STMicroelectronics STTH8S06 as the APFC boost diode. The IC for APFC control is the Champion CM6500UNX.

The electrolytic capacitors on the secondary side are also manufactured in Japan, and they are rated at 105c. These polymer capacitors are from any Japanese company as well; they are made by Chemi-Con, FPCAP, and NIC. For a modern power supply unit, the power output from the rectifiers is +12V. Two Nexperia PSMN1R8-40YLC are responsible for generating +12V, and they can provide current up to 100A continuously at 100c. The +12V output of the power supply unit can just directly use the power from the rectifiers. However, the +5V and +3.3V outputs are converted from the +12V output. The conversion functionality is mainly realized by the components on the DC to DC daughterboard. Meanwhile, there is a Weltrend WT7527V supervisor IC to realize over/under current and over/under voltage protection. More information about the parts mentioned in this review can be found from their respective datasheets from the manufacturer's website.

The modular cable sockets are soldered onto another daughterboard at the rear of the power supply unit. Having good soldering quality of those sockets is very important, since a significant amount of force will be applied on them when plugging or unplugging the connectors. The sockets in the NZXT C650 650W have very good soldering quality, and I am sure that they can handle some abuse with no problem. In the above photo, you can see a smaller board behind the sockets' daughterboard.

In terms of cooling performance, there are two things we need to pay attention to for a power supply unit; namely the heatsink and cooling fan. In this case, we can see a couple of heatsinks and one cooling fan inside of the NZXT C650 650W. The number of heatsinks inside the power supply unit is abundant thanks to the roomy chassis. The size of the fan is 120mm in diameter. A smaller fan is used to keep the enclosure small. According to the label on the fan, the HA1225H12F-Z from the Hong Hua uses fluid dynamic bearings to keep noise and durability in check. From the product's website, we can see the fan can provide up to 73.9 CFM airflow and rated noise level of 32.3dBA at the maximum speed of 2200 RPM.

Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion