SMD Common Mode Chokes LQH-D

The LQH-D Series SMD Common Mode Chokes are designed for effective electromagnetic interference suppression in compact electronic systems.
This series has been independently separated from the legacy Common Mode Choke portfolio to better support clear application guidance and usage-oriented EMC design.

LQH-D chokes are widely used in signal, power, and mixed-signal lines where space efficiency and stable EMI suppression are required.

What Is a Normal Mode Choke?

Many engineers search for what is a normal mode choke, especially when comparing different EMI suppression components.

A normal mode choke is typically used to suppress noise that flows in the same direction as the intended signal or current.
In contrast, a common mode choke targets noise that appears simultaneously on multiple conductors relative to ground.

In practical circuit design:

• Normal mode suppression focuses on differential noise

• Common mode chokes focus on common-mode interference

• Both may be used together depending on EMI severity

The LQH-D Series is optimized specifically for common mode noise suppression, making it suitable for modern EMC-critical applications.

Common Mode Chokes Applications

The common mode chokes applications for the LQH-D Series include a wide range of electronic systems:

• Consumer electronics and home appliances

• Industrial control systems

• Communication and networking equipment

• Embedded power modules

• Interface and I/O signal lines

In many designs, LQH-D chokes are paired with Power Line Common Mode Choke components to achieve system-level EMI suppression.

Key Features of LQH-D Series

• Compact SMD package for space-constrained designs

• Stable inductance and impedance characteristics

• Low DC resistance for reduced power loss

• Suitable for both signal and low-power line applications

• Reliable performance across operating conditions

These characteristics make LQH-D chokes suitable for designers seeking predictable common mode chokes usage in high-density PCB layouts.

Electrical Specifications – LQH-D Series

Selecting Between Normal Mode and Common Mode Chokes

When evaluating what is a normal mode choke versus a common mode choke, designers should consider:

• Noise source characteristics

• Signal sensitivity

• EMC compliance targets

In many applications, common mode chokes such as the LQH-D Series provide more effective suppression of radiated and conducted EMI than normal mode solutions alone.

Integration with Other EMC Components

For optimized EMI performance, LQH-D Series chokes are often used together with:

• ferrite bead inductor for high-frequency noise

• Power Line Common Mode Choke for mains or DC input filtering

• Additional SMD Inductor components for localized suppression

This layered approach enhances overall EMC robustness.

Custom Common Mode Choke Solutions

Ferrtx provides customization services for common mode chokes usage-specific designs, including:

• Inductance and current rating optimization

• Footprint and package adjustments

• Application-driven EMI performance tuning

Our engineering team supports customers from early design evaluation through volume production.

Why Choose FERRTX LQH-D Series?

• Clear separation for application-oriented EMC design

• Stable and reliable common mode suppression

• Compact SMD solution for modern PCB layouts

• Flexible customization and consistent manufacturing quality

The LQH-D Series SMD Common Mode Chokes offer a reliable solution for designers seeking clear guidance on common mode chokes applications and usage, while addressing practical EMI challenges.