Proven Noise Suppression
Engineered EMI/EMC Filters for Mission-Critical Reliability
For over six decades, Astrodyne TDI has researched, designed, and manufactured standard and fully customized electromagnetic interference (EMI) and radio frequency interference (RFI) filters for demanding commercial, medical, industrial, and military applications.
Unwanted electrical noise can degrade system performance, cause digital signal corruption, or lead to regulatory compliance failures during pre-compliance testing. Our line-filtering solutions protect sensitive electronics and mitigate conducted emissions from incoming utility lines and internal high-frequency switching circuits.
Global Regulatory Approvals
Compliant with UL, CSA, CE, UKCA, and IEC agency standards for overseas deployment.
Pre-Compliance Testing
In-house laboratory capability to verify insertion loss and conducted emission margins.
High Power Ratings
Standard platforms engineered for voltage ratings up to 1200 VDC and 600 VAC, up to 2500A.
Low Leakage Options
Medical-grade low-leakage configurations engineered specifically for patient safety.
Comprehensive Portfolio
Industrial & Medical Grade EMI Filter Categories
Explore our high-reliability EMI/EMC filter platforms engineered to satisfy strict attenuation profiles and thermal requirements.
Single Phase EMI Filters
Compact noise filtering for single-phase AC equipment, switching power supplies, PWM drives, and commercial controllers.
3-Phase Delta EMI Filters
Engineered for 3-wire three-phase industrial networks without a distributed neutral. Rated up to 600VAC with robust current handling.
3-Phase WYE EMI Filters
Designed for 4-wire three-phase systems carrying a neutral conductor. Single, dual, and multi-stage configurations for heavy machinery.
DC Line EMI Filters
Standard and custom DC line filters designed for solar arrays, telecommunications power distribution, and battery system decoupling up to 1200VDC.
IEC Inlet EMI Filters
Space-saving filtered IEC power entry modules providing combined noise suppression and power connection for electronic devices.
Tempest EMI Filters
High-attenuation security filters designed to stop high-frequency electromagnetic emanations from leaving secure enclosures over power lines.
Shielded Facility & MRI Filters
High-performance room and enclosure filters isolating clean healthcare environments (MRI suites, shielded labs) from ambient electrical noise.
MIL-COTS EMI Filters
Off-the-shelf defense-grade filters validated for MIL-STD-461 and RTCA/DO-160, operating reliably across extreme temperature ranges (-40°C to +70°C).
Feed-Thru EMI Filters
High insertion loss feed-through suppressors working effectively from kHz to GHz spectrums for mobile shelters and RF cabinets.
Noise Suppression Components
Precision suppression components including safety capacitors, power line chokes, harmonic filters, line reactors, and PFC coils.
Industry Specific Applications
Optimized Filtering for Global B2B Sectors
Different market sectors demand specialized engineering considerations: low patient leakage in healthcare, ruggedized shock resistance in military, and high-harmonic rejection in heavy industrial plants.
Healthcare & Diagnostics
Medical Grade EMI Filters
All standard EMI filter families can be customized into medical-grade configurations featuring controlled line-to-ground Y-capacitance values. This directly limits earth leakage current to comply with safety requirements in patient-contact devices, diagnostic imaging systems, surgical beds, and MRI suites.
- Fully compliant with IEC / EN 60601-1 safety limits
- Ultra-low earth leakage current options
- High immunity against high-frequency surgical arc interference
Defense & Aerospace
MIL-STD-461 Qualified COTS Filters
Designed for severe operating environments, our defense EMI filter platforms deliver off-the-shelf compliance for naval sonar, ground radar, tactical electronics, and airborne systems. Rugged mechanical construction ensures immunity under high shock and vibration conditions.
- Compliance support for MIL-STD-461 and RTCA/DO-160
- Full operational temp capability (-40°C to +70°C without derating)
- Hermetically sealed and potted options available
Custom OEM Solutions
Ground-Up Custom EMI Filter Development
When catalog parts cannot satisfy tight mechanical envelopes, extreme electrical noise levels, or non-standard terminal connector requirements, our global engineering centers design tailored solutions with customized attenuation curves, potting, and mounting brackets.
- Tailored electrical attenuation to pass tricky EMC lab tests
- Custom form factors, busbars, and harness terminations
- Rapid prototyping and full production scalability
Technical FAQ
Frequently Asked Questions by OEM Procurement & Engineers
Key technical insights from our applications engineering team to help simplify your EMI filter selection process.
EMI/EMC filters suppress high-frequency conducted noise generated by fast-switching semiconductors (IGBTs, MOSFETs) inside modern power supplies and drives. Without filtering, noise transfers back into the AC/DC utility grid or corrupts adjacent sensitive control electronics, causing regulatory failures under CISPR, FCC, or EN standards.
A Delta EMI filter is configured for 3-wire three-phase power lines without a neutral conductor, filtering phase-to-phase and phase-to-ground noise. A WYE filter is designed for 4-wire systems with a neutral line, attenuation paths for line-to-neutral noise, and neutral lines rated for full current loads.
Medical-grade EMI filters typically eliminate or drastically minimize line-to-ground Y-capacitors to keep earth leakage current under microamp thresholds mandated by medical safety standards (IEC 60601-1). Industrial filters prioritize higher common-mode noise suppression and use larger Y-capacitors since leakage limits are less restrictive.
Yes. We specialize in both catalog off-the-shelf platforms and custom engineered solutions. If standard filters do not meet your exact attenuation frequency, physical footprint, connector type, or environmental seals, our engineers can customize a filter platform to your exact specification.
Need Custom EMI Filtering or Technical Guidance?
Speak directly with our application engineers to determine the ideal EMI/EMC filter platform for your global program.