TCM & MCZ Ultra-Compact Common Mode Chokes TDK TCM and MCZ wide-band, thin-film, multilayer Common Mode Chokes for EMI suppression are available in several case sizes to accommodate a variety of applications for high-speed data transmission lines. TDK has applied expertise in thin-film magnetic head technology, including original fine pattern conductor formation and film formation technologies, original multilayer structure technologies, and ferrite material technologies.