Common Mode Chokes

Part Number	Description / PDF	Quantity
EXC-24CN601X Panasonic	CMC 200MA 2LN 600 OHM SMD	47563
EXC-24CG360U Panasonic	CMC 130MA 2LN 36 OHM SMD	2035
EXC-14CS900H Panasonic	CMC 100MA 2LN 90 OHM SMD ESD	0
ELF-21V008A Panasonic	COMMON MODE CHOKE 800MA 2LN TH	111
EXC-18CE900U Panasonic	CMC 130MA 4LN 90 OHM SMD	0
ELF-18D850Q Panasonic	COMMON MODE CHOKE 1.9A 2LN TH	238
EXC-14CE121U Panasonic	CMC 100MA 2LN 120 OHM SMD	17315
EXC-24CH500U Panasonic	CMC 160MA 2LN 50 OHM SMD	0
ELF-21C015A Panasonic	COMMON MODE CHOKE 1.5A 2LN TH	380
EXC-34CE201U Panasonic	CMC 200MA 2LN 200 OHM SMD	0
ELF-18D620 Panasonic	CMC 100MH 400MA 2LN TH	765
EXC-24CD900U Panasonic	CMC 160MA 2LN 90 OHM SMD	56
EXC-24CB221U Panasonic	CMC 100MA 2LN 220 OHM SMD	327
ELF-18D613 Panasonic	CMC 3.9MH 2.2A 2LN TH	11
ELF-18D235F Panasonic	CMC 47MH 300MA 2LN TH	505
EXC-18CG430U Panasonic	CMC 100MA 4LN 43 OHM SMD	0
ELF-18D601F Panasonic	CMC 10MH 1.6A 2LN TH	164
EXC-18CS350U Panasonic	CMC 100MA 4LN 35 OHM SMD ESD	820
ELF-18D217 Panasonic	CMC 1.5MH 1.6A 2LN TH	561
ELF-18D412 Panasonic	CMC 6.8MH 1.2A 2LN TH	19

Common Mode Chokes

1. Overview

Common Mode Chokes (CMCs) are passive electronic components designed to suppress electromagnetic interference (EMI) by blocking high-frequency noise currents while allowing DC or low-frequency signals to pass. They play a critical role in ensuring electromagnetic compatibility (EMC) in modern electronic systems, particularly in power supplies, communication interfaces, and industrial equipment.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
High-Frequency CMCs	Optimized for >1 MHz noise suppression	Switching power supplies, USB interfaces
Low-Frequency CMCs	Effective in 10 kHz 1 MHz range	Motor drives, industrial sensors
Multi-Winding CMCs	Multiple coils for differential/balanced circuits	Telecom transformers, Ethernet interfaces
SMD CMCs	Surface-mount design for compact PCB integration	Smartphones, IoT devices
High-Current CMCs	Rated for >10A continuous operation	EV charging stations, solar inverters

3. Structure and Composition

A typical CMC consists of: - Ferrite Core: Made of manganese-zinc (MnZn) or nickel-zinc (NiZn) materials for high permeability - Dual Windings: Symmetrically wound coils with equal turns to maintain signal integrity - Encapsulation: Flame-retardant epoxy resin for mechanical protection - Termination: Tin-plated copper leads or SMD pads

4. Key Technical Specifications

Parameter	Description	Importance
Inductance (H)	100 @ 100 MHz typical	Determines noise suppression effectiveness
Rated Current (A)	0.1 50 A DC	Prevents core saturation under load
Impedance Range	100 MHz 1 GHz	Defines operational frequency bandwidth
DC Resistance ( )	0.01 5	Affects power efficiency
Operating Temp ( C)	-55 to +150 C	Ensures reliability in harsh environments

5. Application Fields

Major industries include: - Consumer Electronics: Laptop chargers, smart TVs - Industrial Automation: PLC controllers, CNC machines - Medical Equipment: MRI scanners, patient monitors - Renewable Energy: Wind turbine inverters, battery storage systems - Telecommunications: 5G base stations, fiber optic transceivers

6. Leading Manufacturers and Products

Manufacturer	Product Series	Key Features
TDK Corporation	ACT1210 Series	1200 @ 100 MHz, 1.5 A rating
Sumida	CDRH3D28 Series	High saturation resistance for EV chargers
Coilcraft	114000C Series	AEC-Q200 qualified for automotive applications
W rth Elektronik	744210 Series	Compact SMD design for 10GbE interfaces

7. Selection Guidelines

Key considerations: 1. Match impedance curve with target noise frequency 2. Derate current capacity by 20% for safety margins 3. Choose SMD variants for automated PCB assembly 4. Verify temperature ratings for industrial applications 5. Prioritize AEC-Q qualified parts for automotive use

8. Industry Development Trends

Current trends include: - Miniaturization through advanced nanocrystalline cores - Integration with TVS diodes for combined EMI/surge protection - Development of 1000+ Amp CMCs for data center power systems - Adoption of RoHS-compliant materials - Implementation of embedded thermal sensors for smart monitoring

Application Case: A server power supply uses TDK ACT1210-600M CMC to suppress 150 MHz switching noise, achieving 40 dB reduction in conducted emissions.