Coilcraft common mode standard packages incorporate several features to help meet the requirements of all major international safety agencies. These include 2 mm thick center flanges and 3 mm creepage and clearance from all terminations to the core.
Common mode chokes are used to reduce AC line conducted interference produced by switching power supplies. This configuration produces opposing magnetic fluxes in the core that serve to cancel in-phase noise signals appearing across the AC line.
This mode allows much more filtering capability in a given core size than would be possible using differential filtering alone. Use of common mode chokes therefore reduces component count as well as inductor size.
Combining both common and differential mode chokes gives the power supply designer the added flexibility required to adjust the filtering to meet FCC, VDE, and other requirements as well as optimize the circuit for the particular noise levels and frequencies produced by each power supply design.
The Coilcraft packaging of common mode chokes allows windings to be balanced within 1% and features the cost effectiveness of standard EE core styles.

• Low cost
• VDE, IEC, UL, CSA compliant
• 3750 Vrms isolation between windings
• Constructed with UL approved Class 130°C insulation system (UL File E83628)
• Industry-standard EE25 size
• Wide range of available inductances and current ratings