Electromagnetic compatibility (EMC) can be the bugbear of a design and solving the EMI filtering issue has never been a straight-forward task. One approach is to tackle EMI in the connectors.
With this in mind connector manufacturer Hypertac has set up an EMI filtering and transient protection facility at its London manufacturing site.
It is possible to improve the immunity of equipment to EMI/RFI and transient energy spikes, both internal and external, by combining filtering components and electronic protection devices within connectors and system interfaces.
An ESD protected filter assembly cleanroom at Hypertac's London facility offers a number of design and manufacturing processes.
These include PCB assembly and build; soldering (PCB, contact, cable, components); complex cable assembly; conformal coating; sub assembly and connector build; ATE and manual testing; potting and curing; component screening; and burn in capabilities.
According to Bill Henderson, technical director at Hypertac: "Having the facility to incorporate filtering and transient suppression within the connector helps us to reduce time to market for our customers."
Issues to be considered include the style of filter used (e.g. C, LC and Pi) and component values selected (up to 1µF). It can provide insertion loss simulations/prediction that account for actual source and load impedances and verify insertion loss performance across the specified frequency range.
Transient protection in accordance with RTCA D160F waveform and level specifications can be provided. The filtering and transient components can then be incorporated within the connectors.
Connector types that can incorporate filtering include military circular (38999, 5015, 26500); rectangular (JN1123, Arinc 600, Arinc 404, 83527); D style (D-Sub 24308, Micro-D 83513); and feed through filter modules.
The company will also provide testing for vibration; mechanical shock; sealing against water and particle ingress; DWV at sea level and altitude; insulation resistance; salt spray; earth bond resistance testing/shell to shell conductivity; durability; thermal shock and cycling; temperature life; cyclic humidity; current de-rating; and transient protection testing.