TDK 450V 1820µF Capacitor Buffers the PFC Bus in a 3300W Server PSU
2026-10-13 · Compiled by Best IT Parts from public industry reporting
A teardown has identified a TDK high-voltage capacitor rated 450V 1820µF on the high-voltage DC bus after the PFC stage of a 3300W server power supply. The unit accepts 100-240V AC and 240V DC input and, on high line, delivers a 54V main output at 61.1A for a maximum output of 3300W. The finding points to the bus capacitor as a key energy buffer in high-density rack power.
In AC input mode the front-end PFC boosts the rectified line to establish the high-voltage DC bus, which the downstream stage then isolates and steps down. The supply is built on a PFC front end followed by an isolated step-down stage, a common arrangement in high-wattage rack power. The 450V 1820µF capacitor sits at that node and handles bus voltage filtering, energy storage and transient power buffering.
Its 1820µF capacity provides a meaningful energy reserve when the server load changes quickly. If the downstream conversion stage momentarily demands more power before the PFC has fully responded, the capacitor releases stored charge to reduce bus voltage variation. The 450V rating covers the boosted bus voltage and leaves margin for normal line fluctuation. On a 3300W platform this capacitor continuously takes part in main power transfer, so its capacity and voltage rating have a direct bearing on overall operating stability.
For buyers tracking 3kW-plus server power, the result confirms that large high-voltage capacitors remain the main energy-buffer node between the PFC stage and the isolated DC-DC stage, and are a component class worth monitoring for replacement-module and board-level sourcing.
Need this part in volume?
Best IT Parts supplies wholesale laptop power adapters, server power supplies and replacement parts, with OEM/ODM and private-label options.
Technical details are reproduced as reported. Verify specifications against the original source before design or procurement decisions.