EMI, Filter Kits

Part Number	Description / PDF	Quantity
MMZ1005-AUTO-KIT TDK Corporation	MMZ1005 AUTO KIT	7
742722 Würth Elektronik Midcom	FLAT FERRITE CORES WE-FLAT	1
B39000Z3410A004 RF360 - A Qualcomm-TDK joint venture	SAMPLE KIT FOR WIRELESS AMI	2
HCTC-KIT Signal Transformer	KIT HIGH CURRENT TOROID CHOKE	10
EK28B0032 Leader Tech Inc.	ENGINEERING KIT - WIDEBAND - BIS	0
MMZ1005-GIGA-KIT TDK Corporation	MMZ1005 GIGA/HIGH SPEED KIT	3
RF-KIT TDK Corporation	DK KIT RF 900MHZ & 2.4GHZ	4
HCTI-HCTC-KIT Signal Transformer	KIT TOROID CHOKE AND INDUCTOR	9
EMI ENG KIT 01 KEMET	EMI CORES	11
EK20B0009 Leader Tech Inc.	ENGINEERING KIT - BLUETOOTH - BI	1
495-77298-KIT TDK EPCOS	PC200 FERRITE CORE KIT	3
K-407 EMI DISC PLT,KIT Laird - Performance Materials	FERRITE EMI DISK AND PLATE KIT	2
EKDMAT04-KIT TOKO / Murata	SMD COMMON MODE CHOKE COILS FOR	2
EK28B0021 Leader Tech Inc.	ENGINEERING KIT - WIDEBAND - SOL	0
EMI ENG KIT 02 KEMET	EMI CORES	2
0199000036 Fair-Rite Products Corp.	MULTI-APERTURE CORE KIT #36	12
UKIT-008BM PulseLarsen Antenna	KIT AECQ XFMR CMC BATT MNGT SYST	0
742700 Würth Elektronik Midcom	EMI SUPPRESSION AXIAL FERRITE BE	7
HIGH CURRENT CMC SAMPLES KIT ITG Electronics, Inc.	COMMON MODE CHOKES SAMPLE BOX	5
K-103LF EMI CM Laird - Performance Materials	KIT COMMON MODE SMD & THRU-HOLE	4

EMI, Filter Kits

1. Overview

Electromagnetic Interference (EMI) filter kits are essential components designed to suppress conducted electromagnetic noise in electrical systems. These passive devices ensure electromagnetic compatibility (EMC) by attenuating unwanted high-frequency signals while allowing desired frequencies to pass. With increasing electronic device density in modern applications, EMI filters play a critical role in maintaining signal integrity, complying with regulatory standards (e.g., FCC, CISPR), and preventing performance degradation across industries such as telecommunications, automotive, and medical equipment.

2. Major Types and Functional Classification

Type	Functional Characteristics	Application Examples
-Type Filters	Three-stage LC configuration with high attenuation at specific frequencies	Power supplies, industrial machinery
T-Type Filters	Asymmetric structure for differential-mode noise suppression	Audio equipment, precision instrumentation
LC Filters	Combination of inductors and capacitors for broad-spectrum filtering	Switching power converters, motor drives
Feedthrough Filters	Low-inductance capacitors for high-frequency noise bypass	Aerospace systems, RF equipment

3. Structure and Components

A typical EMI filter kit comprises: - Capacitors (X/Y capacitors for line-to-line and line-to-ground noise suppression) - Inductors (common-mode chokes for differential noise filtering) - Resistors (for damping and impedance matching) - Enclosures (shielded metal/ceramic packages for mechanical protection) The components are mounted on PCBs or integrated into modular housings, with connections via screw terminals, PCB pins, or wire leads.

4. Key Technical Specifications

Parameter	Importance	Typical Range
Frequency Range	Determines effective noise suppression band	10 kHz - 1 GHz
Rated Voltage	Defines maximum operational voltage	12 V - 600 V AC/DC
Insertion Loss	Measures noise attenuation capability (dB)	10 dB - 100 dB
Current Rating	Specifies maximum continuous operating current	0.1 A - 100 A
Impedance Matching	Ensures minimal signal reflection	50 - 600

5. Application Fields

Telecommunications: 5G base stations, fiber optic transceivers
Medical Equipment: MRI machines, patient monitors
Industrial Automation: PLCs, CNC machine controllers
Transportation: EV charging stations, onboard chargers
Consumer Electronics: Switching power supplies, LED drivers

Case Study: In electric vehicles, EMI filters reduce conducted noise from inverters, ensuring compliance with CISPR 25 standards for automotive EMC.

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
Schaffner Group	FN 2000 Series	High-performance industrial filters up to 100 A
Murata Manufacturing	NFM Series	Ceramic feedthrough filters for GHz-range applications
TDK Corporation	ACT Series	Common-mode chokes for automotive powertrains
EPCOS (TDK)	B84143 Series	Three-phase filters for industrial motor drives

7. Selection Guidelines

Key considerations include: - Frequency Requirements: Match filter's cutoff frequency to target noise spectrum - Environmental Conditions: Temperature (-55 C to +150 C), humidity, and vibration resistance - Space Constraints: Miniaturized SMD packages vs. panel-mount solutions - Compliance Standards: Regulatory requirements (e.g., MIL-STD-461G for military) - Cost vs. Performance: Balance between insertion loss and budget limitations

8. Industry Trends

Emerging developments include: - High-Frequency Optimization: Filters for 5G mmWave (24 GHz+) and EV charging systems - Integration: System-in-Package (SiP) EMI solutions combining filtering and power management - Smart Materials: Nanocrystalline alloys for high-permeability, low-loss cores - Environmental Compliance: RoHS-compliant, halogen-free filter designs