The common source radio frequency (RF) noise from a product design comes through the conductive cables from device to device. Wavelengths leaking through these paths can result in interference.

One solution has been the development of filtered connectors, which incorporate shielding material structured around the hardware of the connector assembly.

A newer approach to connector EMC has been EESeal® filter inserts from Quell. These silicone precision inserts form a tight fit around the pins of most connectors. Design engineers can shunt noise at the same output point of a filtered connector and achieve comparable results.

Lab testing—as well as thousands of real-life cases of successful EMI compliance—demonstrate the reliable performance of EESeal filter inserts to suppress RF noise. Additionally, the inserts stand up to a wide range of harsh environmental conditions, from altitude and immersion to shock and vibration.

Let’s examine these two options in terms of EMI suppression performance, design flexibility, and cost.

EMI Shielding Performance

The problem of EMI, and the subsequent obstacle of achieving compliance, is that the frequencies that breach the desired threshold are somewhat unpredictable and can vary from application to application. EMI filtering methods that succeed across frequencies in one project may fail to suppress a range on the high end or lower end of another similar project.

Therefore, interference solutions are not a one-size-fits-all proposition. A degree of trial and error may be necessary, particularly at the end prototype stage of product development–or even later in the field during system integration.

Though there are numerous topologies of filtered connectors on the market, the overall strategy is to offer an across-the-board standardization to make the most viable product for the greatest number of customers. This middle-of-the-road approach, however, might not satisfy requirements in cases where a range of noise frequencies are more extreme than usual. The lack of variety can be a disadvantage of filtered connectors.

Variety and Customization

EESeal inserts come in an array of filtering options for the same connector configuration, each with varying pin treatment to protect the integrity of data throughput. Some inserts protect RS422 data on specific pins, while others protect CAN commands on different pins.

It is far easier to try out an EESeal sample while prototyping rather than to have to go back and source an entirely new hardware component.

In particularly hard-to-meet specifications, custom EESeal solutions can be designed, fabricated, and shipped to you within 24 hours.

Quell will even send the custom sample to you free of charge.

Cost and Availability

Given comparable EMC performance in nearly any standard connector configuration, EESeal inserts have the advantage of lower cost.

Of course, the cost savings of not having to reschedule additional trips to the EMI lab can add up to thousands of dollars.

The EESeal solution typically beats out specialty connectors on a per-unit basis as well.

Much of the cost of the filtered connector comes not from the functional materials, but from the mechanics that contain it. Filtered connectors simply have more subcomponents and manufacturing costs, resulting in prices significantly higher than a thin elastomeric insert.

It simply takes a lot more to build filtered connectors, so they can run generally 25% to 50% more expensive than the EESeal solution. Comparing an individual filtered connector on the site of a major distributor to that of its standard-issue counterpart will sometimes show a price many times higher.

This logic of cost can extend into the product lifecycle. Not only are standard connectors cheaper because of the sheer volume produced than built-in EMI specialty connectors, they are more accessible in the supply chain during production and later once a product is in the field.

Adding EESeal inserts to common connector types is easy, requiring no special training or soldering and can be performed by non-technical personnel.

The specific cost comparison will depend on the specific requirements of the system and the performance levels needed. Consult with a qualified EMI/EMC engineer at Quell to find definitive pricing and the best solution for your specific needs.

Whatever the particulars, rest assured you can get the full value of reliable noise suppression with EESeal inserts at a lower cost.