Feedthrough Filter

Product Specifications

Technical details and manufacturing context for Feedthrough Filter

Definition

A feedthrough filter is a passive EMI suppression component that is mounted directly into the wall of a shielding enclosure. Its primary function is to allow electrical conductors—such as wires, cables, or connector pins—to pass through the enclosure boundary while maintaining electromagnetic compatibility (EMC). It achieves this by filtering conducted interference at the point of entry, preventing external electromagnetic noise from entering the enclosure and internal noise from escaping. This preserves the integrity of the shielded environment, which is critical in applications like military electronics, medical devices, telecommunications, and industrial control systems.

The filter typically consists of a cylindrical metal housing that is threaded for panel mounting, with a central conductor passing through. Inside, passive components—capacitors and inductors—are arranged in configurations such as pi, T, or L networks. These components create a low-impedance path to ground for high-frequency noise, while allowing desired signals or DC power to pass with minimal attenuation. The metal housing is bonded to the enclosure to maintain continuous shielding.

Feedthrough filters are available in a range of electrical and mechanical specifications. Rated voltage typically spans 50–1000 V DC, and rated current from 1–50 A. Insertion loss is generally at least 40 dB when measured from 100 MHz to 1 GHz per MIL-STD-220. Capacitance values range from 100–10000 pF, and operating temperature covers -55°C to 125°C. Insulation resistance is at least 100 MΩ at 500 V DC after humidity testing, and dielectric withstanding voltage is 500–3000 V DC for one minute without breakdown. Mechanical options include thread sizes from M3 to M12 (ISO 965), body diameters from 6–25 mm, lengths from 10–50 mm, and weights from 5–100 g. Environmental protection is rated IP65 to IP68 per IEC 60529.

These parameters are reference ranges; actual values must be confirmed with the manufacturer for the specific model and application. Always verify that the selected filter meets the required standards and performance criteria for your installation.

Working Principle

The feedthrough filter operates by using passive components—typically capacitors and inductors—arranged in pi, T, or L configurations. These are installed directly on the enclosure wall at cable entry points. The filter creates a low-impedance path to ground for high-frequency noise, while allowing desired signals or DC power to pass through with minimal attenuation. The metal housing of the filter maintains continuous shielding by bonding directly to the enclosure, ensuring that the shield's integrity is not compromised at the penetration point.

Common Materials

Ceramic dielectric (for capacitor elements), Ferrite core (for inductive elements), Metal housing (typically brass or stainless steel), Glass or epoxy seal

Technical Parameters

Parameter	Typical range	Notes & selection driver
Rated Voltage	50–1000 V DC	Higher voltage requires larger dielectric clearance.
Rated Current	1–50 A	Current rating depends on conductor cross-section and temperature rise.
Insertion Loss	≥40 dB	Measured at 100 MHz to 1 GHz per MIL-STD-220.
Capacitance	100–10000 pF	Higher capacitance improves low-frequency filtering.
Operating Temperature	-55–125 °C	Exceeding range may degrade dielectric and solder joints.
Insulation Resistance	≥100 MΩ	Measured at 500 V DC after humidity test.
Dielectric Withstanding Voltage	500–3000 V DC	Test voltage applied for 1 minute without breakdown.
Thread Size	M3–M12 mm	Common sizes for panel mounting.ISO 965
Body Diameter	6–25 mm	Determines panel hole size and mounting torque.
Length	10–50 mm	Affects insertion loss and mounting space.
Weight	5–100 g	Approximate for standard configurations.
IP Rating	IP65–IP68	Higher rating for harsh environments.IEC 60529

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Filter Element Part
Provides the actual filtering through capacitor and/or inductor networks

Material: Ceramic/ferrite composite
Housing/Body Part
Mechanical structure that mounts to enclosure and contains filter element

Material: Brass or stainless steel
Terminals/Pins Part
Electrical connection points for internal and external wiring

Material: Copper alloy with plating
Seal/Insulator Part
Provides electrical insulation and environmental sealing

Material: Glass or epoxy

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Shielding Enclosure

View system integration details

Manufacturers of Feedthrough Filter

Manufacturer profiles associated with Feedthrough Filter.

Sourcing Feedthrough Filter from China?

Tell us your specification and target quantity — we will match it against manufacturer records and come back with the factories that fit.

Request manufacturers We manufacture this

Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Frequently Asked Questions

What is the primary function of a feedthrough filter?

A feedthrough filter is designed to allow electrical conductors to pass through a shielding enclosure while suppressing conducted electromagnetic interference. It prevents external EMI from entering the enclosure and internal EMI from escaping, maintaining electromagnetic compatibility.

How do I select the correct feedthrough filter for my application?

Selection depends on the electrical requirements such as rated voltage, rated current, capacitance, and insertion loss. Also consider mechanical factors like thread size, body diameter, length, and environmental protection (IP rating). Always verify the specific model's parameters with the manufacturer to ensure it meets your application's needs.

What standards are relevant for feedthrough filters?

Common standards include MIL-STD-220 for insertion loss measurement, ISO 965 for thread sizes, and IEC 60529 for IP ratings. These standards provide reference methods and specifications, but they do not guarantee that a particular product is certified or compliant. Always check with the supplier for actual compliance.

What are typical failure modes of feedthrough filters?

Typical failure modes include dielectric breakdown due to overvoltage, degradation of solder joints from excessive temperature, and loss of capacitance due to aging or moisture ingress. Regular inspection and testing, such as insulation resistance and insertion loss measurements, can help detect potential issues early.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

Buyer enquiry

Request manufacturing insight for Feedthrough Filter

Ask for use case, specification boundaries, supplier type, and RFQ preparation information for this product.

Where it goes: Straight to the CNFX editorial desk, and to the manufacturer if this product is linked to a claimed profile. Nothing is broadcast to a supplier list.
Your details stay here: We do not sell or rent enquiry data, and we do not add you to a mailing list. Used only to answer this request.
No commission, no middleman: CNFX is a directory. We take no cut of any order and never negotiate on a supplier's behalf.
What we don't claim: A listing is not an endorsement. Qualify every supplier and verify every figure yourself before ordering.

pressure:	0 to 100 psi
other spec:	Frequency range: 10 Hz to 40 GHz
temperature:	-40°C to +125°C

Product Specifications

Applied To / Applications

Industrial Ecosystem & Supply Chain Structure

Application Fit & Sizing Matrix

Reliability & Engineering Risk Analysis

Compliance & Manufacturing Standards