A Look Inside And Component Analysis
Parts Description
Before proceeding with this page, we strongly encourage you to a look at our PSUs 101 article, which provides valuable information about PSUs and their operation, allowing you to better understand the components we're about to discuss. Our main tools for disassembling PSUs are a Thermaltronics soldering and rework station, and a Hakko 808 desoldering gun.
| Primary Side | |
|---|---|
| Transient Filter | 4x Y caps, 2x X caps, 2x CM chokes, 1x MOV |
| Inrush Protection | NTC Thermistor & Diode |
| Bridge Rectifier(s) | 1x |
| APFC MOSFETs | 2x Infineon IPA60R125CP (650V, 16A @ 100 °C, 0.125 ohm ) |
| APFC Boost Diode | 1x STMicroelectronics STTH8R06FP (600V, 8A @ 100 °C) |
| Hold-up Cap(s) | 1x Rubycon (450V, 390uF, 3000h @ 105 °C, MXG) |
| Main Switch | 1x STMicroelectronics STF25N80K5 (800V, 12.3A @ 100 °C, 0.26 ohm) |
| Reset Switch | 1x CET CEF03N8 (800V, 2A @ 100 °C, 4.8 ohm) |
| APFC/Switching Controller | FSP 6600 IC |
| Topology | Primary side: Active Clamp Reset Forward Secondary side: Synchronous Rectification & DC-DC converters |
| Secondary Side | |
| +12V MOSFETs | 2x |
| 5V & 3.3V | DC-DC Converters: 6x Infineon IPD031N03L G PWM Controller: 2x FSP6601 |
| Filtering Capacitors | Electrolytics: Nippon Chemi-Con (105 °C, KY, KZE) Polymers: FPCAP (1x), Nippon Chemi-Con (1x) |
| Supervisor IC | Weltrend WT7527 (OVP, UVP, OCP, SCP) |
| Fan Model | Protechnic Electric MGA13512XF-O25(135mm, 12V, 0.38A, Fluid Dynamic Bearing) |
| 5VSB Circuit | |
| Rectifier | 1x STPS20L60CT (60V, 20A @ 140 °C) |
This platform uses an Active Clamp Reset Forward (ACRF) topology, which allows for high efficiency with the use of fewer components compared to full- and half-bridge topologies with LLC converters. We've seen this implementation before in Rosewill's Capstone G1200. A synchronous design is used for the secondary side's +12V rail, while the minor rails are regulated by two DC-DC converters. All filtering capacitors are provided by Nippon Chemi-Con, enhancing this platform's reliability.
The ACRF topology provides high efficiency at lower cost since there's no need for an LLC resonant converter or (low RDS-on) FETs. In this case, we have a single power switch ACRF design, where one FET acts as the main switcher (Q1), while a second one serves as the reset switch (Q2). The reset switch's job is to disconnect the APFC converter's bulk capacitor when Q1 is active. When Q2 is open, power is transferred from the primary to the secondary side. This design allows for almost lossless switching of the Q1 FET, as its drain voltage is very low when it's off. A single Infineon SPW60R099C6 FET acts as the Q1 switch, and a Fairchild FQPF3N80C is the Q2 reset switch.
The first part of the transient filtering stage begins at the AC receptacle with a couple of Y caps. It continues on the mainboard with two Y and a pair of X caps, along with two CM chokes. Unfortunately, there is no MOV (the part that protects the PSU and the system it feeds from power surges).
A small NTC thermistor provides protection against large inrush currents. It is bypassed by a diode instead of the electromagnetic relay that we usually find in Gold- and higher-rated PSUs.
The single bridge rectifier is bolted on a dedicated heat sink.
In the APFC converter, two Infineon IPA60R125CP FETs are used along with a single STMicroelectronics STTH8R06FP boost diode. The single bulk cap is provided by Rubycon (450V, 390uF, 105 °C); although its capacity is low, thanks to the ACRF topology, it provides a pretty long hold-up time.
The main switch is an STMicroelectronics STF25N80K5 FET and the reset FET is a CET CEF03N8. We also find a CET CEF02N7G FET on the other side of the primary heat sink, though it appears to interact with the 5VSB circuit. The combo PFC/PWM switch is an FSP6600, which is soldered on the component side of the mainboard.
The +12V FETs, two in total, are installed on a small heat sink. Unfortunately, we aren't able to identify them. All filtering capacitors on the secondary side are provided by Nippon Chemi-Con and are rated at 105 °C. We also find two polymer caps, one by FPCAP and one by Chemi-Con. Indeed all caps in this PSU are by Japanese manufacturers, as EVGA states.
The parts that rectify the minor rails are installed on the solder side of the mainboard. In total, six Infineon IPD031N03L G FETs are used and their PWM controllers are two FSP6601 ICs, with the latter installed on a vertical board in the secondary side. Above the PWM controllers are two pots (potentiomenters) with unknown, at least to us, functionality.
The supervisor IC is a Weltrend WT7527, which supports OCP for up to two +12V rails (even though this PSU only has one).
At the front side of the modular PCB is free space for installing additional filtering caps, though EVGA apparently decided it didn't need them. That's a shame, since this platform doesn't have good ripple suppression.
The 5VSB rail is rectified by an STPS20L60CT SBR (Schottky Barrier Diode).
Soldering quality is pretty good, as is usually the case in FSP products.
On the solder side of the PCB, aside from the DC-DC converters, we also find some interesting parts, including three shunt resistors under the +12V island. Normally these resistors are used by the OCP circuit. But there's only one +12V rail on this unit, so the shunts aren't exploited.
The fan is made by Protechnic Electric and its model number is MGA13512XF-O25 (135mm, 12V, 0.38A). It's a high-quality fan, and because of the Fluid Dynamic Bearing it uses, it should last a long time. The only problem is that the fan is very noisy at high speeds and its control circuit is pretty aggressive when the operating temperature or the load applied to the PSU increases.
