MX8683

IXYS

Application Example

This application example illustrates one method of incorporating the MX8683 into a power circuit board

design. The double-sided 8oz copper traces carry 20A (10A on the top trace and 10A on the bottom

trace) around the center section of the planar E-core. The MX8683 is mounted on a small single layer

flex circuit that effectively adds a third layer. The flex also fans out the fine pitch DFN package to a pitch

compatible with the power board. The magnetic circuit consists of two ferrite E14 planar cores. The

center post of one of the cores is gapped to accommodate the MX8683 package thickness plus the flex

circuit thickness. For the 20A full scale application a gap of 47 to 52 mils is appropriate (1.2 to 1.32 mm).

The gain trim range of the MX8683 can accommodate even larger gaps if required.

Flex circuit

MX8683

(2) E14 planar cores

Cross Section (drawing not to scale)

PCB top layer: (scale 1X)

PCB bottom layer: (top view, 1X)

Flex circuit: (component side, 1X)

Design alternatives:

Multi-layer boards may be used with the MX8683 mounted directly on the board.

The use of an E-I core pair results in a lower profile than E-E however a thinner board must be used.

An example of a low-power circuit board with an added high-current copper strap:

MX8683

Copper stamping, thickness as required

MX8683

8

03/03/08

Drawing No. 0868309

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