Contents
- 1Introduction
- 1.1Packaging and accessories
- 2Connectors & cabling
- 2.1Casing & cooling
- 3Input filtering
- 4Primary side
- 4.1+5 V stand-by rail
- 5Secondary side
- 5.1Build quality
- 6Load testing
- 6.1Loading +5 V SB
- 6.2Voltage hold-up time
- 6.3Combined loading
- 6.4Combined loading ripple
- 6.5Crossloading, overloading
- 6.6Crossloading, overloading ripple
- 7Conclusion and evaluation
- 7.1Thanks
- 7.2Discussion
Primary side
The primary side starts with GBU15L06 bridge rectifier. It handles 15 A continuous (with heatsink) at 600 V and 115 °C or 450 A surge (1 ms, 125 °C) with a voltage drop of 0.9 V per diode at 7.5 A and 25 °C. In this case it has a small, golden-colored heatsink mounted on it but together they are covered with insulation tape, I guess the cooling will not be so good this way. The PFC coil is basically a transformer type with the windings mostly closed inside the core. Transistors in PFC are two Infineon IPA50R190CE (18.5/63 A at 25 °C and 500 V, Rds(On) 190 mΩ at 6.2 A and 25 °C, 450 mΩ at 150 °C), mounted on common primary heatsink (with black anodising). The ST Microelectronics STTH8R06FP diode (8/30 A at 600 V and 130 °C, drop of 2.9 V at 8 A and 25 °C) is mounted on a separate small heatsink. Everything in TO-220F package. 
The capacitor charged by PFC circuit is CapXon LP 270 μF/420 V for 85 °C (measures 236 μF) with endurance of 2000 hours. Could be much better and I am very curious if this thing is going to handle the minimum ATX hold-up time. The PFC circuitry together with primary switching is driven by proprietary FSP 6600 IC which has its supply voltage filtered by a C(r)apXon GF 47/35 capacitor. Switching transistor is Infineon SPA17N80C3 (17/57 A at 25 °C and 800 V, Rds(On) 0.29 Ω at 11 A and 25 °C, 0.78 Ω at 150 °C) combined with Fairchild FQPF3N80C (3/12 A at 25 °C and 800 V, Rds(On) 4.8 Ω at 1.5 A) for the clamping. Again both in TO-220F package. 
+5 V stand-by rail
The stand-by rail is also being controlled from within the proprietary FSP 6600 chip. A CET-MOS N-FET is used for switching, the CEF03N8 (3/12 A at 25 °C and 800 V, Rds(On) 4.8 Ω at 1.5 A) in TO-220F package, mounted on the common primary heatsink. An auxiliary winding of the stand-by transformer (20mm core) used to power the driving IC and transistors is filtered by C(r)apXon GL 100/50 capacitor. Not a very good choice, when this one goes bad, the whole PSU stops working.
On the secondary side is the ST Micro STPS20L60CT rectifier (20/30 A at 140 °C and 60 V, drop of 0.74 V at 20 A and 25 °C) in TO-220 package. Both diodes are in parallel, however, it is insulated with heatshrink, that will definitely not help the cooling. Filter consists of two Nippon Chemi-Con KZE 3300/10 capacitors.
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