X2Y Chip Devices Syfer / Knowles X2Y Chip Devices are 3-terminal EMI chips that provide simultaneous line-to-line and line-to-ground filtering using a single ceramic chip. The X2Y series features differential and common mode attenuation and eliminates the effects of temperature and voltage variation. The X2Y EMI chips also include higher voltage versions. Syfer / Knowles X2Y Chip Devices are ideal for use in balanced lines, twisted pairs, and DC motors in automotive, audio, sensor, and other applications.