Filtered connectors simplify design for EMC

Polamco has developed a range of planar array filtered connectors in collaboration with a renowned filter technology specialist.

Today's increase in frequency and power of electromagnetic interference (EMI) or electronic noise has become a major threat to the integrity of modern electronics equipment.

Developing equipment designs that will operate within today's electromagnetic environment and be compatible with the worldwide electromagnetic legislation is now essential.

This requires that the equipment functions as intended, without being adversely affected by any electromagnetic interference and without being the source of such interference.

For equipment to be protected against radiated interference sources it is necessary to screen equipment from any EMI.

For small numbers of signal lines and where there is space for an internal bulkhead, individual discrete lowpass EMI filters may be successfully used.

However, the space required to accommodate these discrete filters becomes prohibitive as the number of input, output and power lines grows in line with today's trend to typically reduce equipment size and increase its functionality.

A practical solution is to incorporate multipole EMI filtering elements within a connector shell.

Advantages of this solution include further space savings, reduced assembly cost and simplification of equipment enclosure design.

The optimum way of providing these filtering elements is through the use of planar capacitor arrays.

Polamco has developed a range of planar array filtered connectors in collaboration with a renowned filter technology specialist.

The use of a unique compliant pin and ground contact techniques together with optimal thermal profiles during assembly ensure a high-reliability construction for the most demanding of military, aerospace and industrial applications.

Devices are available in MIL-C-26482 and 38999 connector styles with flexibility to accommodate variety of connector shell dimensions.

The use of these connectors may provide advantages of simplified equipment assembly, reduced costs and improved space efficiency through the elimination of any 'clean/dirty' bulkhead.

Within each filtered connector shell it is possible to incorporate any combination of unfiltered feedthroughs and independent capacitance and filter configurations, such as C, LC and Pi, on each signal or ground line.

Further protection can be provided against short fast-rise-time transients experienced, for example during switch on power surges and lightning strikes.

The advantages of planar arrays in signal and power line filtering are: filtering occurs at the optimum interference of the equipment being protected; the capacitance provides DC isolation between the signal lines and ground; low crosstalk between lines; and a short earth path for the high-frequency noise on the line.

To provide optimum insertion loss the planar array is assembled into the connector so as to provide earthing over the entirety of the perimeter of the array.

Further protection may be provided against short fast-rise-time transients experienced for example during switch on power surges and lightning strikes.

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