WE-TFC & WE-TFCH Common Mode Chokes Würth Elektronik WE-TFC and WE-TFCH Common Mode Chokes feature 1% stray inductance for symmetrical interference suppression. They suppress common-mode noise up to 70dB and have an optimized frequency range of 10kHz to 100MHz. Other features include high isolation between the windings, climatic category 40/125/21, and UL 94V-0 flammability rating. Würth Elektronik WE-TFC and WE-TFCH Common Mode Chokes are ideal for use in mains filters, compact switched-mode power supplies, lighting, and white goods applications.