Every electronic prototype displays some unpredictable electromagnetic interference (EMI) behavior, even when designers put their best efforts into shielding, grounding, and incorporating off-the-shelf filter components into the circuit.

The noise leakage from the device — or its negative performance response to certain environmental frequencies — is typically first discovered when the prototype is at an internal lab or testing agency.

When lab results fall short of standards, graphs show that mitigation efforts worked for the most part across the spectrum, but there remain spikes or short ranges of frequencies above the threshold for regulatory compliance.

The secret not known among all electrical engineers is that these extreme areas can be targeted by a simple modification post hoc — without the need to redesign circuits or rebuild prototypes. The solution is custom EESeal® EMI filter inserts.

Customization is Standard Practice

EESeal silicone inserts fit into most standard connectors and act as an extension of your circuit outside of the casing, which is often the perfect point to mitigate any unwanted interference issues. Miniature passive components and traces embedded in the high-dielectric silicone connect to your application through the pins. Each pin can be treated uniquely.

The assortment of these micro-components — such as capacitors, resistors, diodes and more — can vary in configuration to target different parts of the spectrum. The EESeal filter insert typically adds a C-filter with low inductance to provide 40 to 45dB of attenuation at a given frequency.

At Quell, there is no standard product stocked in a warehouse. Each EESeal insert is made to order based on the test results of your device, focusing on the problematic frequency ranges of your EMI test. Every filter is custom and designed for the exact application. Quell’s claim to fame is that it can design, build, and ship a custom product sample in 24 to 48 hours.

In the world of electronics, the term “customization” might suggest an extreme action and last resort. Most custom electronic components come with high factory costs, MOQs, extended timelines, and extra engineering hours to design the part and collaborate with fabricators.

This is not at all the case with EESeal filter inserts. A can be shipped to you completely free. Samples are available to you fast enough to try it out while you’re still at the testing lab.

EMI Protection at the Pins

Our experienced technicians will match the most appropriate filter components and configurations to the type of interference problem and span of frequencies involved.

Although these outside-the-circuit circuits are small enough to require a microscope to assemble, the EESeal solution can have huge impacts on the EMI profile of all sizes of electronic systems.

The low cost and ease of installation (non-technicians can insert the filters in connectors without solder or tools) makes the post-hoc modification preferable over the alternative — redesigning the PCB with added discrete components, which takes far more budget and engineering hours, not to mention the long lead times for new orders.

An EESeal filter insert proves effective in the “general EMI” part of the spectrum. Higher-end radio frequencies, from 20 to 100GHz, are best suppressed with Quell’s EESeal+® insert.

Likewise, pin-connected connector modifications can be employed to boost capability for grounding in the form of gaskets. Quell also offers embedded diodes to combat electrostatic discharge (ESD) and transients.

Getting Started with your Custom Insert

At first it may be shocking to learn that one small disc can change the fate of a development project for a multi-million-dollar system, but this happens time and time again for EESeal customers.

The first step is to contact the technicians at Quell. They can use information about your prototype, including EMI feedback from lab tests and the type, size, and pin configuration of your connectors, to spec out a custom sample.

Ordering samples is both free of cost and free of risk. Your customization can be express-delivered to you the following day, allowing you to try them in operation at the testing facility or before crucial deadlines.

If the samples work to attenuate frequencies below the compliance specifications like MIL-461 or DO-160, it is easy to incorporate the connector modification into your final product. EESeal filter inserts are designed for production and for the life of the product. The silicone rubber compression ensures reliable connectivity despite shock and vibration, extreme temperatures, and mold and moisture ingress.

Quell can generate a large quantity of custom inserts to meet your timeline, no matter the size of your production run. Find out more about this simple modification from Quell and order your free custom sample today.