Smiths Connectors is now Smiths Interconnect


Filter Connector Transient Protection

The increased sensitivity of electronic systems and mandated performance requirements such as RCTA DO-160 make transient protection paramount in system design today. Transient suppression built into the connector provides the most space efficient and effective method of protection against Electromagnetic Protection (EMP), Lightning, Nuclear EMP and voltage transients. The excess energy is shunted to ground at the connector interface before it can even enter the system. With the advent of today’s high signal transmission speeds coupled with low-level operating voltages, a need for high speed EMP protection circuitry has arisen. Smiths Connectors has developed a complete series of EMP products ideally suited for this need. Densely packaged and protected within the connector shell, Smiths Connectors employs the use of low voltage TVS bi-polar diode connected in series to a parallel network of back-back rectifiers as shown in the schematic diagram.


TVS diodes are mounted inside the connector around the periphery of the insert arrangement. Standard “catalog” diodes are utilized as opposed to custom or downsized diodes in order to increase reliability and minimize cost. JANTX diodes can be supplied; however, Smiths Connectors has the capability to prescreen diodes with component level testing and burn-in which eliminates infant mortality.

The connector shell dimensions vary with the quantity and type of diodes chosen, but generally fit within the outline defined by the mounting flange. Smiths Connectors’s method of mounting the diodes can be incorporated into any connector type including, but not limited to MIL-DTL-38999, ARINC 600 and ARINC 404.

Where required, transient protection can be combined with EMI/RFI filtering to provide maximum protection. The diodes as well as the EMI filter are packaged separately so that the construction of the connector remains modular. Therefore, individual diodes as well as the EMI filter can be removed or replaced without disassembling the connector.

Transient Curves

In order to meet the ever increasing EMC system requirements by our customers, Smiths Connectors offers solutions for both EMC and EMP protection on high speed data lines. For Coax, Triax and Twinax contact types, Smiths Connectors has a unique design solution that offers tailored protection without degradation to the data signals being transmitted. This is accomplished by maintaining extremely low capacitance and leakage current levels on custom designed diode stacks, with high frequency EMC filters.

Manufactured in a robust modular manner, the connectors can be quickly disassembled from the front/rear providing access to the diode stacks for removal/replacement if they become damaged as a result of excess transients experienced in service. Operating frequencies in excess of 100 MHz can be successfully used with full EMC/EMP protection, fully safeguarding the equipment and offering a low risk / high performance solution.


Surface Mount Technology for Transient Protection

Smiths Connectors can also offer transient protection in our connectors utilizing surface mount technology (SMT) chip diodes. These can be provided as an alternative to axially leaded components in instances where availability or source of supply problems could potentially become an issue. SMT diodes are provided by numerous manufacturers and distributors and in most cases readily available as they are widely used in the electronics industry. The incorporation of SMT components can potentially provide space and weight savings as well based on the particular connector and application requirements. If you have any questions in regards to SMT technology please contact Smiths Connectors for further information.