EMI filter packaging: CHIP SCALE PACKAGES ENHANCE PERFORMANCE

摘要

Most consumer electronic products today, especially handheld devices, require protection from electromagnetic interference (EMI). To accomplish this, they need filtering devices that are small, inexpensive, and can reject radio frequency interference (RFI) and interference from high-frequency clocks and other signal harmonics. A major concern for all wireless devices is interference caused by very high frequencies of RF transmission. An EMI filter both suppresses unwanted emissions and improves immunity to the transmissions of other RF devices, typically noise at frequencies above 800 MHz and as high as 2.5 GHz. To accomplish these tasks, appropriate filters must be used. Chip scale packages (CSPs), because of their tiny form factor and associated low inductance, enable good filter performance by permitting this high-frequency rejection.