General through-hole common mode chokes utilize T-cores and thicker wire to handle higher current, making them ideal for AC-DC converters, power adapters, and DC-DC front-end filtering. For SMD types, Coilmaster supports both power-line CMC (MnZn) and high-frequency signal-line CMC (NiZn). Different winding structures—bifilar or sectional winding—are selected based on required Hi-Pot strength, impedance, and differential-mode loss. Engineers must select the most suitable structure depending on working frequency, current, EMC limits, and board layout.

How to choose the suitable common mode choke

When selecting a CMC, consider: • Required working frequency (Power <1MHz / Signal up to GHz) • Current capacity & temperature rise limits • Target impedance and inductance • Need for high isolation (sectional winding) or low differential-mode loss (bifilar) • Whether MnZn, NiZn, or nanocrystalline is best for the specific noise spectrum you must suppress

Key Differences You Should Know

Characteristic

High-frequency suppression
MnZn & NiZn material options
Sectional or bifilar winding
EMI Stability
High impedance at wide frequency range

Features

• Effective in high-frequency noise suppression.
• Does not distort differential signals.
• Excellent common-mode impedance from kHz to GHz.
• Available in SMD & THT, from signal to high-current applications.
• Custom inductance, impedance, and core materials available. High Inter-Winding Isolation (THT) / Low Differential Capacitance (Signal Line)

Applications

• Power-line filtering (AC-DC, DC-DC converters)
• Signal-line differential pairs (USB, HDMI, CAN, RS485)
• Inverters, motor drivers, EV chargers
• Communication devices, telecom modules
• Industrial 3-phase power filtering and high-power EMC compliance