Tiny filter repels EMI/ESD away from wireless functions
By Bill Schweber -- EDN, July 7, 2005
As wireless phones get smaller and pack in more auxiliary functions, such as cameras, the potential for EMI problems increases, whereas the space available to squelch these problems shrinks. The Centurion CM1430 and CM1431 filter arrays from California Micro Devices combines EMI filtering with ESD protection in a low-profile, 0.4-mm-high package. These four-, six-, and eight-channel devices implement capacitor-resistor-capacitor pi-filter topologies with cutoff frequencies of 200 and 120 MHz and 1-GHz attenuation of 25 and 35 dB, respectively, for the CM1430 and CM1431 (Picture).
ESD protection reaches ±15-kV contact discharge, as IEC61000-4-2 Level 4 specifications dictate. Lead pitch is 0.4 mm, compared with 0.5 mm for previous packages. The 0.1-mm difference results in a board footprint reduction as great as 40%. The devices’ prices range from 42 to 59 cents (1000).
California Micro Devices Corp, www.calmicro.com.
