Treat the panel connection as part of the filter
At the shield boundary, a panel feedthrough filter carries the line conductor and diverts conducted interference toward the bonded panel. Choose its electrical network and mechanical installation together: published attenuation depends on the test circuit, and the body-to-panel connection is part of the filtering path.
Panel-mounted conductor feedthrough EMI filters and feedthrough capacitors, including screw-in bodies with C, L-C, Pi or T networks. Chassis, DIN-rail and IEC-inlet mains filter assemblies are on the EMI filter page. Vacuum/pressure-boundary electrical connectors are on the Electrical feedthrough (vacuum and hermetic) page; PCB bypass chips, RF bandpass filters and enclosure shells are separate products.
01
Knowles explains that published insertion loss uses a source/load test circuit whose impedances may differ from the equipment. It also identifies ferrite saturation under load current as a cause of reduced attenuation in inductive filter networks. [1]
Specify the wanted signal or power, noise spectrum, source/load impedances and operating current. Ask for attenuation evidence under the relevant load, bias and installation conditions, along with the exact C, L-C, Pi or T configuration offered.
WEMC lists feedthrough filters/capacitors separately from its mains-filter assemblies. Identify whether the offer is a capacitive element or a multi-element network before comparing order codes and attenuation data. [3]
| Functional item | Information to match to the circuit and panel |
|---|---|
| Filter element | Capacitance/dielectric and any inductive elements, circuit topology and attenuation conditions. |
| Housing / body | Mounting form, conductive bond to the shield panel and installation envelope. |
| Terminals / pins | Conductor rating, connection method, lead geometry and mechanical support. |
| Seal / insulator | Electrical insulation and the specified environmental construction; distinguish resin sealing from a separately qualified hermetic boundary. |
02
Syfer’s SFLM Issue 2 sheet specifies a screw-in M5 body for a tapped hole and a maximum mounting torque of 0.3 N·m. Its installation notes require the body to be grounded to the panel and warn that mounting stress can damage the ceramic. These instructions apply to that documented design. [2]
Obtain the panel-hole/thread drawing, thickness constraints, seating face and assembly-tool instructions for the selected filter. Agree how coatings, finishes, washers and the surrounding shield construction provide the specified conductive interface.
Follow the selected product’s soldering and lead-handling instructions, with support for connected wires and clearance from the body. Request inspection criteria for cracks, damaged threads, loose bonds and insulation faults. Verify attenuation in the completed equipment where the RF boundary and wiring are present.
03
The 2014 Syfer sheet lists SFLMC5000102MX0 as a C filter with 1.0 nF X7R capacitance, 500 V DC rated voltage and 750 V DC dielectric withstand. Its attenuation entries are given as typ. values. Request the current approved sheet for the exact order code and test conditions. [2]
Specify model-specific insulation and equipment safety requirements with the filter supplier and equipment designer. A filtering data sheet supplies electrical component data; qualification of the completed enclosure and equipment needs its own evidence.
| Filter field | Evidence to obtain |
|---|---|
| Rated voltage | Continuous AC/DC operating limit, applied bias and the selected dielectric/configuration. |
| Rated current | Conductor heating limit and, where inductors are fitted, attenuation under the intended current. |
| Insertion loss | Frequency range, source/load impedances, bias/load conditions, fixture and typ./minimum status. |
| Capacitance | Nominal value, tolerance, dielectric and change with bias, temperature and aging. |
| Operating temperature | Component and installed environmental limits with current/temperature derating. |
| Insulation resistance | Test voltage, conditioning, measurement duration and acceptance limit. |
| Dielectric withstanding voltage | Applied test voltage, waveform/duration and test points; keep separate from continuous working voltage. |
| Thread size | Complete thread designation and required panel-hole tolerance on the drawing. |
| Body diameter | Head/body geometry, seating face, tool access and clearance. |
| Length | Panel/body/lead envelope and protected connection space. |
| Weight | Selected filter and included mounting hardware. |
| IP rating | Evidence for the selected installed sealing arrangement if ingress protection is required. |
04
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Line: [DC/AC/signal; voltage; current; wanted signal band] Noise: [frequency range; source/load impedances; load/bias conditions] Filter: [C/LC/Pi/T; capacitance/dielectric; attenuation evidence] Panel: [material/finish; hole/thread; thickness; conductive bond] Acceptance: [insulation tests; installed attenuation; environmental requirements]
WEMC lists feedthrough filters/capacitors. Send the line duty, interference band and panel drawing, and request the exact circuit, attenuation conditions and mounting instructions for its proposed model.
Feedthrough filters/capacitors listed for EMI suppression. Confirm the chosen circuit, conductor rating and mechanical/panel interface from the model-specific drawing.
Product scope checked 2026-10-19
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Knowles explains that source/load impedance and current affect insertion loss. Confirm the operating circuit and installed result. [1]
The Syfer example gives separate rated-voltage and dielectric-withstand columns. Keep both with their stated test conditions. [2]
WEMC groups filters and capacitors together. Obtain the circuit configuration and exact order code. [3]
Sources checked 2026-10-19. Knowles’ 2019 technical article discusses circuit-dependent attenuation. The Syfer SFLM Issue 2 document is a 2014 design example; obtain the current controlled version for procurement. WEMC establishes its own feedthrough range, without transferring its catalogue claims to other filters.
Ask for use case, specification boundaries, supplier type, and RFQ preparation information for this product.
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