Disassembly
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The G-450’s input filtering starts at the AC receptacle, with an X-Capacitor, coil and four Y-Capacitors. The main PCB adds another X-Capacitor, 1.5 coils (one only goes over Active/Line, but not Neutral), two Y-Capacitors and one MOV, bringing the total component count to two X-Capacitors, 2.5 coils, six Y-Capacitors and one MOV, which is plenty of components. Four Infineon IP50R399CP Transistors are present on the primary side – two PFC transistors and two switching transistors. They are rated for 9A at 25°C and 6A at 100°C and have a Drain-Source Resistance, or RDS-on of 0.399Ω. The PFC transistors are controlled by an Infineon ICE3PCS01G APFC Controller IC, and the switchers are driven by an ICE2HS01G Resonant controller. The primary side capacitor is a 330µF part supplied by the Japanese Nippon Chemi-Con.
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The other electrolytic capacitors are supplied mostly by Chemi-Con, although some of them are supplied by Rubycon – another very reliable Japanese brand. There are also some polymer capacitor supplied by Enesol – a Korean company.
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The 12V rail uses the same semi-synchronous design as the 350GT and interestingly, the same silicon components are also used – two NXP PSMN2R640YS MOSFETs and two Diodes Inc. SBR10U45 schottky rectifiers. These components are more than good enough for the labelled 37A, and are also used by the more powerful G-550. The other two rails use DC-DC conversion from the 12V rail, which is more efficient than having separate rectification circuits. There are seven Infineon IPD060N03L MOSFETs used on the DC-DC VRMs – four on the 5V rail and three on the 3.3V rail. They are rated for 50A, regardless of the temperature, and 0.006Ω RDS-on. I couldn’t find any information or a datasheet on the IC that controls the VRMs. The main secondary side controller IC is a Silicon Touch PS223. It supports Over Temperature Protection (OTP), Under Voltage Protection (UVP), Over Voltage Protection (OVP) and Over Current Protection (OCP) for up to two 12V Rails, although the manufacturer opted not to take advantage of this and only use a single 12V rail.
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The soldering is generally very tidy, with the exception of a few hand-done joints. There are no loose solder blobs, or any joints without enough solder.
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The fan is the same model used on the 350GT – an ADDA ball bearing part. It has maximum speed, airflow and noise ratings of 2200RPM, 87.87CFM, and 39dB respectively. It was also very quiet until we approached full load. It was never disturbingly loud, though. The heat sinks are a sufficient size for an efficient 450W product.
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