A Look Inside & Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the internal components of a PSU much better. Our main tool for the disassembly of the PSU is a Thermaltronics TMT-9000S soldering and rework station. It is of extreme quality and is equipped with a matching de-soldering gun. With such equipment in hand, breaking apart every PSU is like a walk in the park!


Using the same platform as Seasonic's G-series models, The XTR-650 is manufactured by Seasonic, like all other XTR units. The unit uses a pretty modern high-quality platform you can call affordable. Using components of quality, our experience with the platform also shows it to offer good and reliable performance. The primary side uses a half-bridge topology and an LLC resonant converter, which boosts efficiency, while the secondary side utilizes two DC-DC converters to generate the minor rails, with a semi-synchronous design for the rectification of the +12V rail. Lots of polymer caps and several Japanese electrolytic caps handle ripple suppression.


Behind the AC receptacle is the small PCB most Seasonic units use. It hosts four Y caps, one X cap, and a CM choke. The transient filter continues on the main PCB with two more CM chokes, two Y caps, a single X cap, and an MOV.


Here is Seasonic's leaning heatsink that holds the bridge rectifier. The latter is a GBU10V08


In the APFC, two Infineon fets and an STTH8S06D boost diode are used. The hold-up cap is provided by Hitachi (390µF, 420V, 105°C, HU series). Right in front of it is the thermistor responsible for protection against large inrush currents.


This vertical daughter-board houses an ICE2HS01G resonant controller (large IC on the left) and an ICE3PCS01 PFC controller (small IC on the right). The resonant controller operates in Pulse-Frequency-Modulation (PFM) in which the repetition rate (or frequency) of fixed-duration pulses varies unlike with PWM, where the width of square pulses is varied at a constant frequency. In order to avoid high frequency switching, the aforementioned controller employs Missing Cycle Mode with light loads and Burst Mode with no load.


Two Infineon fets are used as primary switchers, but their markings were unfortunately beyond recognition. The fets are arranged into a half-bridge topology.


A semi-synchronous rectification scheme with two PSMN2R6-40YS fets and two SBR10U45 Schottky diodes rectifying the +12V rail is utilized in the secondary side. These come installed to the solder side of the main PCB, and a heatsink on the component side helps lower their operational temperature. The minor rails are generated by two DC-DC converters.


Several Enesol polymer caps, some electrolytic Chemi-Con caps, and a few Rubycon caps, all rated at 105°C, handle the ripple in the secondary side.


The standby PWM controller is an Infineon ICE2QR4765 IC. The Schottky diode responsible for the rectification of the 5VSB rail is an SBR10U45, and it is located on the solder side of the main PCB.


The supervisor IC is a SITI PS223. It is among the few with support for OTP (Over Temperature Protection).


On the front of the modular PCB are three Chemi-Con caps and a small Rubycon cap for some extra ripple filtering.


As expected because Seasonic manufactured this PSU, soldering quality is good.


The cooling fan is by Hong Hua, and its model number is HA13525H12F-Z (135 mm, 12 V, 0.5 A, 2300 RPM max). We believe this specific fan to be too strong for the needs this Gold-certified PSU.