Contents
- 1Introduction
- 1.1Packaging and accesories
- 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
- 6.2Combined loading
- 6.3Combined loading ripple
- 6.4Crossloading, overloading
- 6.5Crossloading, overloading ripple
- 7Conclusion and evaluation
- 7.1Thanks
Primary side
This unit is basically the same as Antec TP-550C or Seasonic G-550 I have already reviewed, but since none of those have been here yet, I will go more thoroughly. The primary side begins with a bridge rectifier, the Lite-On GBU10V08. It handles current of 10 A continuously/250 A surge (for 8.3 ms, 500 A for 1 ms) at 800 V and 25 °C. Voltage drop is 0.92 V per diode (at 5 A). The rectifier also has its own small heatsinks with some fins. The transistors in PFC (boost-type) circuit are Infineon SPP50R250CP (13/31 A at 25 °C and 550 V, on resistance (Rds(On)) is 250 mΩ at 7.8 A and 25°C, 0.54 Ω at 150 °C) in TO-220 package. The power diode in PFC is an ST Micro STTH8S06 (8/60 A at 600 V and 175 °C, voltage drop of 3.4 V at 8 A and 25 °C) in TO-220AC package. PFC coil is quite massive with thick enough wire used for winding.
For my taste and high-end, I would like to see much more overrated components in there, as is usual in high-end. The capacitor charged by PFC circuit is Nippon Chemi-Con KMR 330 μF/420 V with 2000 hours@105 °C specified lifetime, I have measured value of 289 μF, this is on the low side. OEM version of this supply has 390μF (even though Teapo for 85 °C), quality 390μF capacitor would be preferred here. Switching transistors are two SPP50R250CP, same as used in the PFC but with their own heatsink. The PFC circuitry is driven by Infineon ICE3PCS01G controller, switching transistors than by ICE2HS01G resonant LLC controller, both are located on a small daughterboard on the left side and have their supply rail filtered by a Rubycon YXG 10 μF/50 V capacitor. The main transformer has 42mm wide core.
+5 V stand-by rail
The stand-by rail in most of the Seasonic units on the market starting with SSP-350GT now uses Infineon ICE2QR4765 quasi-resonant PWM controller with integrated transistor for 650 V so there is no exception for the Seasonic S12G 550 W. Its supply rail is filtered by a Rubycon YXG 100 μF/50 V capacitor.
Behind the EF20 transformer is SBR10U45 (10/125 A at 45 V and 110 °C, voltage drop of 0.57 V at 10 A and 25 °C) rectifier in TO-252 (DPAK) SMD package, soldered on the bottom side of the PCB. Nippon Chemi-Con wet electrolytic capacitors are used for output filtration of the stand-by rail, a KZH 3900 μF/16 V (D12.5) before Pi coil and KZE 3300/10 (D10) after Pi coil. Only high-quality capacitors so far, I like this.