
High density AC-to-DC front-end modules offer isolation and PFC benefits
Featuring a universal AC input range (85 – 264 VAC), power factor correction, and a fully isolated 24 VDC or 48 VDC output, and delivering 400 W of isolated, regulated, DC output power at efficiencies up to 93%, the modules provide unprecedented power density of 127 W/in3 (8 W/cm3) and best-in-class performance in a 9 mm thin VIA package. The units are ideally suited for use in a broad range of industrial, process control, telecommunications, office equipment, test and measurement, LED lighting and other ‘off-line’ applications.
Every electronic product or system that operates off of an AC utility line must incorporate an AC-DC ‘front end’ to convert the AC utility voltage into the smooth DC voltage required by electronic circuitry. These new units integrate a full range of front-end functions required by contemporary AC line-operated power systems – transient and inrush current protection; input power factor correction; input to output isolation; and a regulated SELV (Safety Extra Low Voltage) DC output – and meet international safety and regulatory agency standards for isolation, conducted emissions, power factor correction, and susceptibility to AC line transients, flicker, interruptions and surges. VIA package configurations are available for both on-board mounting and chassis mounting and units are available in two operating temperature ranges.
In many applications, a user can instantly implement a complete AC-DC front end by simply combining a PFM with an AIM (Universal AC Input Module), which integrates all required primary-side rectification, filtering and transient protection circuitry), both in VIA packages and suitable secondary-side storage capacitance. Alternatively, a designer can combine a PFM front-end module with rectification, filtering and secondary-side output capacitance that is optimised for a specific application.
In either case, the PFM front-end module offers a quick and easy pathway to a rugged, high-performance, high-density AC-DC front-end solution, while eliminating the uncertainties and long design cycles associated with a custom front-end design. And, whereas many alternative front end systems are configured with capacitive energy storage at the high-voltage input, the PFM offers enhanced system safety by storing energy in low voltage capacitors at the isolated SELV output.
At one-fifth the thickness of traditional ‘1U’ front-end solutions, the mechanically robust, thermally adept VIA package simplifies mounting to an equipment side panel, chassis or other external heat sinking device and provides improved thermal performance in any application. Moving the AC-DC conversion function to a chassis or side panel can reduce system size and cost, or free up valuable system real estate for other uses, and can provide improved thermal performance while eliminating the need for, and cost of, external heat sinks.
Offering power systems designers a rugged, modular, fully integrated AC-DC front-end solution with much higher power density than alternative products, the PFM AC-DC front-end modules are compatible with a wide variety of available downstream power conversion components. By using Vicor’s online suite of PowerBench design tools to combine PFM AC-DC front-end modules with downstream modules selected from Vicor’s comprehensive portfolio of high-density, high-efficiency, modular power converters, power architects can rapidly design and deploy complete off-line power systems featuring predictable performance and unrivaled power density, efficiency and reliability.
