Part Analysis
| General Data | |
| Manufacturer (OEM) | CWT |
| PCB Type | Double-Sided |
| Primary Side | |
| Transient Filter | 6x Y caps, 2x X caps, 2x CM chokes, 1x MOV |
| Inrush Protection | 1x NTC Thermistor SCK207R0 (7 Ohm @25°C) & Relay |
| Bridge Rectifier(s) |
2x GBJ1506 (600V, 15A @ 100°C)
|
| APFC MOSFETs |
2x STMicroelectronics STF33N60M2 (650V, 16A @ 100°C, Rds(on): 0.125Ohm)
|
| APFC Boost Diode |
1x CRMicro CRXI08D065G2 (650V, 8A @ 165°C)
|
| Bulk Cap(s) |
1x Teapo (420V, 560uF @ 105°C, TD(M))
|
| Main Switchers |
2x STMicroelectronics STW33N60DM2 (650V, 15.5A @ 100°C, Rds(on): 130mOhm)
|
| APFC Controller | |
| Resonant Controller |
Champion CM6901X
|
| Topology |
Primary side: APFC, Half-Bridge & LLC Resonant converter
Secondary side: Synchronous Rectification & DC-DC converters |
| Secondary Side | |
| +12V MOSFETs | 6x InPower Semiconductor FTG014N04SA (40V, 145A @ 100°C, Rds(on): 1.4mOhm) |
| 5V & 3.3V | DC-DC Converters: 4x UBIQ QN3107M6N (30V, 70A @ 100°C, Rds(on): 2.6mOhm) |
| Filtering Capacitors | Electrolytic: 8x Chengx (2-3,000h @ 105°C, GR) Polymer: 3x Teapo (FP), 9x BIOSTAR, 19x |
| Fan Controller | Nuvoton MS51FB9AE |
| Fan Model | ZIC ZFF132512H (135mm, 12V, 0.45A, Fluid Dynamic Bearing Fan) |
| 5VSB | |
| Rectifier |
1x Dongke Semiconductor DK5V45R10S (45V, 10A)
|
| Standby PWM Controller |
On-Bright OB2365T
|
The OEM is Channel Well Technology, which is one of MSI’s strongest partner OEMs. The small PCB isn’t overloaded with parts, and the airflow is quite good, thanks to the large distance between most components, especially on the secondary side. Close to the main transformer, which has standard dimensions, we find the 12V FETs, soldered on the PCB’s business side. Typically, the PCB’s designer chose to bring these FETs as close as possible to the main transformer to minimize energy losses on power transfers. All main filtering capacitors on the secondary side are positioned on the clear, allowing for unobstructed airflow. The DC-DC converters handling the minor rails are installed on a vertical board, which is located very close to the modular PCB. Having the DC-DC converters as close as possible to the PSU’s outputs increases efficiency, as it minimizes power transfer losses.
The transient filtering stage contains all the necessary components to block both incoming and outgoing EMI emissions. Typically, it starts at the AC receptacle and continues on the main PCB.
There is an MOV to protect from voltage surges and an NTC thermistor with a resistance of 10 ohms. Moreover, a bypass relay supports the NTC thermistor.
The two GBJ1506 parallel bridge rectifiers can handle up to 30A combined.
The APFC converter uses two STMicroelectronics STF33N60M2 FETs and one CRMicro CRXI08D065G2 boost diode. Teapo manufactures the bulk capacitor. Its capacity is 560 μF, and it is rated for 2,000 h at 105 °C. It is nice to see a 420V capacitor instead of a 400V one, which is too close to the APFC’s DC bus voltage (approximately 380V DC).
The APFC controller is a Champion CM6500UNX. It is supported by a Sync Power SPN5003, which reduces vampire power consumption.
The two STMicroelectronics STW33N60DM2 primary switching FETs are installed in a half-bridge topology, and an LLC resonant converter is used for higher efficiency.
The LLC resonant controller is a Champion CM6901X.
The PSU’s main transformer. It doesn’t feature a crazy design, so its dimensions are standard and not overly compact.
Six InPower Semiconductor FTG014N04SA FETs regulate the 12V rail. They are installed on the business (top) side of the main PCB, and two small heatsinks handle their cooling.
Two DC-DC converters generate the minor rails. They use four UBIQ QN3107M6N FETs. The PWM controller is hidden from view, unfortunately.
ChengX provides the electrolytic filtering capacitors. I have visited this factory and found the production quality to be satisfactory. The polymer caps are by Teapo, BIOSTAR, and another brand, which I was unable to identify.
You can find more information about capacitor performance and other specs below:
The standby PWM controller is an On-Bright OB2365T, and the secondary side rectifier is a Dongke Semiconductor DK5V45R10S.
Several polymer caps at the face of the modular panel form an extra ripple-filtering layer.
The soldering quality looks good.
The cooling fan is a ZIC ZFF132512H, utilizing a fluid dynamic bearing. The fan controller is a Nuvoton MS51FB9AE. I prefer a Hong Hua instead, but apparently, this would increase the production cost.
