EMI/RFI Chokes Coilcraft EMI/RFI Chokes help ensure reliable high-speed data interface communication that is free of disruptive EMI. These EMI/RFI Chokes are effective and widely used interface circuit components for meeting the variety of signal size, thermal variation, and spectral density requirements in high-speed communications. Coilcraft common mode chokes help maintain the integrity of high-speed communications and may be necessary for FCC and international regulatory standards conformance.