38999 Series III-Type EMI Filter Connectors, Marine Grade
C or π filter per contact · up to 55 dB · marine grade
EMI Filter and Transient-Protection Connectors
38999-type connectors with a low-pass filter or transient suppression in every contact — EMI/RFI and surge protection at the enclosure wall.
Electronics must keep external interference out and their own high-frequency noise in. A filter connector puts a low-pass filter on every contact, so noise is shunted to the shell at the enclosure wall.
Our filter connectors use planar C or π filter arrays from 75 pF to 100 nF with up to 55 dB insertion loss at 100 MHz, in 38999 Series III (threaded) and Series I (bayonet) types. They keep the standard mating interface to fit existing wiring, and are marine grade.
Compare series
| Series | Filter circuits | Capacitance | Insertion loss | Coupling | Temperature |
|---|---|---|---|---|---|
| J599 III filter | C or π | 75 pF to 100 nF | Up to 55 dB at 100 MHz | Triple-start thread | −55 to +125 °C |
| GJB599 I filter | C or π | 75 pF to 100 nF | Up to 55 dB at 100 MHz | Bayonet | −55 to +125 °C |
| TVS | −55 to +125 °C |
38999 Series I-Type Bayonet EMI Filter Connectors, Marine Grade
Bayonet · C or π filter per contact · marine grade
TVS Transient-Protection Connectors, Marine Grade
Surge, lightning and ESD protection in the connector
How to choose
Frequency to suppress
Pick capacitance by cut-off frequency: 100 nF for 0.1 MHz up to 75 pF for 70 MHz.
C or π
π filters give steeper attenuation (up to 55 dB at 100 MHz).
Working voltage
50, 100, 200 or 400 VDC classes; DC circuits only.
Surges and inductive loads
Tell us about spikes, relays and motors so we can size the filter correctly.
Options beyond the standard connector
TVS transient protection
Surge, lightning and ESD suppression in the connector.
38999 Series III connectors
Standard non-filter versions.
Frequently asked questions
What information do you need for a filter connector?
Base connector part number, pin-out with signal type, frequency, maximum voltage and current per contact, and the insertion loss or capacitance you need. We will return a filter proposal.
From sample to production
Send your requirements
Part number, drawing, pin-out or a short description of your application.
Configuration and quote
Our engineers match the configuration and reply with a drawing and quotation.
Samples
Samples are built to order. The minimum order quantity is 10 pieces, and samples and production orders each take 4–8 weeks. Third-party testing to your specification is available on request.
Your approval
You test the samples in your own equipment and approve them.
Series production
Production follows the approved sample configuration, with machining, molding, plating and assembly in our own Shenyang factory.
Need a quote or a drawing?
Send your part number, pin-out or drawing. Every inquiry is acknowledged by email within 1 business day, and an engineer follows up with a matched configuration, drawing or quotation.