SMD Common Mode Chokes SBA

The STRF Series SMD Common Mode Chokes are designed as chokes for data and signal lines, providing effective suppression of common-mode noise while preserving signal integrity.
This series has been independently separated from the legacy Common Mode Choke portfolio to better address high-speed data transmission and sensitive signal applications.

STRF common mode chokes are optimized for compact PCB layouts, stable impedance performance, and reliable EMI control in modern electronic systems.

What Are Common Mode Chokes for Signal Lines?

Many engineers ask: are common mode chokes necessary for data and signal lines?
In practical EMC design, the answer is often yes.

A line common mode choke is used to:

• Suppress high-frequency common-mode noise

• Reduce EMI emissions on differential signal pairs

• Improve system-level EMC compliance

Unlike power-line chokes, chokes for data and signal lines must maintain low insertion loss and minimal signal distortion.

Line Common Mode Choke Operation

The line common mode choke operates by utilizing coupled inductors on the same magnetic core:

• Differential signals generate opposing magnetic flux, resulting in low impedance

• Common-mode noise currents generate reinforcing flux, creating high impedance

• Unwanted EMI is attenuated without affecting data transmission

This principle makes STRF chokes suitable for high-speed digital and analog signal environments.

Why Use STRF Chokes for Data and Signal Lines?

The STRF Series is engineered specifically for signal-sensitive applications where traditional EMI components may degrade performance.

Key Advantages

• Optimized for data and signal lines

• Stable impedance across wide frequency ranges

• Low DC resistance to minimize signal loss

• Compact SMD Inductor footprint for high-density PCB designs

• Reliable performance under continuous operation

STRF chokes are often used alongside ferrite bead inductor and Multilayer Chip Inductors in layered EMI suppression strategies.

Typical Applications

STRF chokes for data and signal lines are widely applied in:

• USB, HDMI, and high-speed data interfaces

• Communication modules and networking equipment

• Industrial control signal lines

• Consumer electronics signal paths

• Measurement and Sensor signal transmission

They are commonly integrated into system-level EMI Filter and Power Line Filters architectures.

Are Common Mode Chokes Necessary in Signal Integrity Design?

In high-speed and low-noise systems, the question “are common mode chokes required?” depends on EMI levels and compliance targets.

In many cases, line common mode chokes:

• Reduce radiated and conducted EMI

• Improve compliance margins

• Protect sensitive signal paths

STRF chokes offer a balanced solution where EMI suppression is achieved without compromising signal quality.

Integration with Other EMI Components

For comprehensive noise control, STRF series chokes are often combined with:

• SMD Common Mode Chokes for multi-line suppression

• Ferrite Bead Inductor for localized high-frequency noise

• Power Line Common Mode Choke for system-level EMI control

This layered approach enhances overall EMC performance.

Custom Chokes for Data and Signal Lines

Ferrtx supports custom line common mode choke solutions for signal-specific applications, including:

• Impedance and inductance tuning

• Package size and footprint customization

• Frequency response optimization

• Application-driven EMI performance targets

Our engineering team works closely with customers from design evaluation through mass production.

Why Choose FERRTX STRF Series?

• Dedicated chokes for data and signal lines

• Independent STRF series classification for precise selection

• Proven line common mode choke performance

• Custom design support and stable production quality

The STRF Series SMD Common Mode Chokes provide reliable EMI suppression for modern data and signal transmission systems where performance and integrity are critical.