LCF Common Mode Noise Filters Littelfuse LCF Common Mode Noise Filters cover the specification for engineering requirements for high-speed differential series interfaces, such as USB 3.1, USB 2.0, MIPI, D-PHY, or HDMI. Littelfuse LCF Filters are effective for suppressing common-mode noise and have almost no effect on high-speed differential data lines. These filters feature a differential mode cut-off frequency of up to 8.78GHz at -3dB.