New Praetorian EMI Filters for Wireless Handsets

California Micro Devices introduced the CM1418 and CM1419, the newest members of the Praetorian ASIP (Application Specific Integrated Passive) EMI (electromagnetic interference) inductor-based filter array family, offering superior filter performance combined with robust ESD (electrostatic discharge) protection.

The CM1419 device is tailored for audio applications in wireless handsets, where minimizing insertion loss is absolutely critical. Traditional filters based on resistor-capacitor (R-C) architectures result in significant power loss. To address this requirement, CMD has utilized its Praetorian process technology allowing the integration of spiral inductors with capacitors, diodes and resistors on a single chip, resulting in unprecedented attenuation levels and minimal insertion loss in a compact 5 bump CSP (Chip Scale Package) format. The CM1418 features the same electrical characteristics in a larger 6 bump footprint.

The CM1419 is an inductor-based EMI filter array with ESD protection, which integrates two Pi filters (C-L-C). Component values are 117pF-3.0nH-117pF for each channel. The ESD diodes connected to the filter ports are designed and characterized to safely dissipate ESD strikes of +/-30kV, beyond the maximum requirement of the IEC61000-4-2 international standard. Using the MIL-STD-883 (Method 3015) specification for Human Body Model ESD, the pins are protected for contact discharges at greater than +/-30kV. The CM1419 features attenuation levels greater than -40dB in the critical 800 MHz to 2.1 GHz frequencies range. It is housed in a cost effective, ultra compact 5-bump, 0.5mm pitch Chip Scale Package of 1.59mm x 1.22mm.

The CM1419 is particularly well suited for speaker applications in mobile handsets because it features an equivalent series resistance (ESR) of only 0.28Ohms typical, which needs to be as low as possible in order to minimize insertion loss, contributing to better audio output as well as extended battery life. Combined with an extremely small footprint and unmatched attenuation levels, the CM1419 addresses all critical requirements from wireless handset designers: best electrical performance, most integrated and compact format, cost effectiveness and power savings.

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