Abstract
M.Ing.
A constant demand exists for ever decreasing size in switch mode supplies. The
first step has been the introduction of resonant mode converters. Such converters
typically consist of a resonant tank, a transformer and an input or output filter. The
soft-switching characteristics of these converters allow an order of magnitude
higher frequency, thus reducing the size of the reactive components.
The next logical step towards a smaller package is introduced, namely the
electromagnetic integration of the resonant tank and, if possible, the transformer
into a single component, which; not only saves mass and volume, but can also
reduce manufacturing costs. The particular converter investigated is the well
known series resonant converter. It is shown that the necessary capacitance can
be achieved by using a bifilar primary and the leakage inductance of the
transformer replaces the physical inductor.
Simulation of a suitable distributed circuit network indicates the same frequency
domain characteristics and time domain waveforms for both the integrated
component, and the discrete inductor, capacitor an transformer in series. Possible
configurations for the integrated LCT-component are proposed, and theoretical
analysis predicts an operating frequency in the MHZ region.
Notwithstanding the complicated manufacturing, results show An integrated
LCT-component, applied in a prototype 1 MHz power supply, with an efficiency of
approximately 90 %. If manufacturing of the LCT-component allows an acceptable
dimension and an acceptable resonant frequency, this can be a very competitive
technology.