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Discover nowCommon Mode Chokes – Effective EMI Solutions from alfatec
In modern electronic circuits, electromagnetic compatibility (EMC) and signal integrity are critical. Unwanted interference can impair functionality or even cause failure.
A common source of such interference is common-mode noise. This is where common mode filters, also known as common mode chokes, come into play.
alfatec GmbH & Co. KG, as an experienced distributor, offers a wide range of high-quality chokes from renowned partners Sunlord and Chemi-Con to reliably protect your designs against common-mode issues.
What Are Common Mode Chokes and How Do They Work?
Common mode chokes are passive inductors specifically designed to suppress unwanted common-mode noise while allowing differential signals to pass through with minimal impedance. They typically consist of two identical windings on a shared core - often made of manganese-zinc (MnZn) or nickel-zinc (NiZn) ferrite - to achieve the desired magnetic properties.
- Common-mode signals: Currents flowing in the same direction on two or more conductors (e.g., supply and return lines), often causing unwanted radiation or coupling.
- Differential signals: Currents flowing in opposite directions on the conductors, representing the useful signal.
The choke’s winding structure causes the magnetic flux of differential currents to cancel out, resulting in low impedance. In contrast, the flux of common-mode currents adds up, creating high impedance and effectively attenuating the noise.
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Key Technical Parameters for Selection
When selecting a common mode choke, consider the following parameters (available in datasheets):
- Impedance vs. Frequency: Indicates the choke’s attenuation performance across frequencies.
- Rated Current: Maximum continuous current per winding without overheating or saturation.
- DC Resistance (DCR): Ohmic resistance of the winding; lower DCR minimizes voltage drop and power loss.
- Rated Voltage: Maximum voltage between windings or between winding and core.
- Insulation Resistance: Resistance between windings or winding and core, indicating isolation quality.
- Operating Frequency Range: The effective frequency range of the choke.
- Operating Temperature Range: Temperature range within which the choke performs reliably.
- Materials: Ferrite cores (NiZn for high frequencies, MnZn for lower frequencies); windings typically enamelled copper wire.
Types of Common Mode Chokes in the alfatec Portfolio
alfatec offers various form factors to meet your specific application needs:
1. SMD Common Mode Chokes (Surface Mount Device):
- Ideal for automated assembly (reflow soldering)
- Compact designs for space-constrained applications
- Commonly used in data lines (USB, Ethernet, CAN), telecom, and consumer electronics
- Available in advanced technologies, including thin-film for high-frequency performance
2. Through-Hole Common Mode Chokes (Radial Pin / THT):
- Typically more robust, suitable for higher currents and voltages
- Larger ferrite cores for higher inductance or current capacity
- Used in power supplies (line filters), industrial and power electronics
- High attenuation across a broad frequency range
alfatec covers both SMD and THT types through Sunlord and Chemi-Con, ensuring compatibility with diverse design requirements.
Our partner for Wire Wound Common Mode Filters
Sunlord
Our partner Sunlord has been developing and producing chip-based electronic components such as EMC or RF components, coils, inductors and transformers since 2000. The company also offers development work for customised designs and has already received Tier 1 certifications for this.
Chemi-Con
As the world's largest manufacturer of aluminium electrolytic capacitors, Chemi-Con has been driving development in this field since 1931. The core product portfolio is supplemented by other innovative components such as tantalum electrolytic capacitors, film capacitors, supercapacitors and many more, so that the manufacturer is characterised by a wide range of standard and special types of high quality, reliability and performance.
Partner Highlights:
- Sunlord: Known for miniaturization, excellent high-frequency performance, SMD components optimized for reflow soldering, and innovative thin-film technologies. Ideal for automotive, telecom, and consumer electronics.
- Chemi-Con: Strong in power supply and industrial applications, focusing on reliability and performance, with robust THT components for demanding environments.
Why Choose Common Mode Chokes from alfatec?
alfatec GmbH & Co. KG is your trusted partner for high-quality common mode chokes. We offer:
- Broad Portfolio: SMD and THT chokes from leading manufacturers Sunlord and Chemi-Con
- Technical Expertise: Our engineers help you select the right component for your application
- High Availability: Fast delivery through efficient logistics and inventory
- Competitive Pricing: Attractive terms, especially for medium and large volumes
- Reliable Partnership: We value long-term customer relationships and excellent service
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See for yourself the quality and performance of our common mode filters/common mode chokes. Request a non-binding quote today or download the data sheets.
alfatec – your partner for high-quality electronic components
As your expert partner for electronic components, alfatec supports you in selecting the right common mode filters/common mode chokes for your applications. We offer comprehensive advice and are happy to answer any questions you may have about power modules.
Do you have questions about our common mode filters/common mode chokes or would you like a personal consultation? Feel free to contact us.