Product Overview
California Micro Devices announces the CM1405, an eight channel electromagnetic interference (EMI) filter array with electrostatic discharge (ESD) protection for the LCD interface of mid- to low-tier cell phones. The CM1405 can also be used to provide EMI filtering and ESD protection for data ports and buses in wireless handsets, PDAs, MP3 players and mobile accessories. The 8 channel CM1405 provides a lower overall cost per channel solution than the 6 and 4 channel devices available on the market today. California Micro Devices’ proprietary Centurion™ advanced zener process ensures a lower equivalent series resistance (ESR), resulting in improved high frequency attenuation characteristics.

The CM1405 is manufactured as a chip scale packaged (CSP) device and is available with Optiguard™ coating for improved assembly. The CM1405 is also available with preformed eutectic (63Sn/37Pb composition) or lead-free (96.8Sn2.6Ag0.6Cu composition) 0.30mm solder spheres for attachment.

Product Features
The CM1405 was designed for EMI suppression on clamshell phones, which typically utilize a flexible PCB to connect the main PCB board to the LCD display and camera module in the "flip" portion of the phone. This flexible PCB inherently radiates RFI which needs to be suppressed in order to maintain proper operation and EMC compliance. To achieve this, the CM1405's Pi-filters attenuate unwanted RF noise at better than 35dB between the carrier frequencies of 800MHz to 2.7GHz. In addition, the CM1405 maintains attenuation at greater than 30dB at frequencies beyond 2.7GHz. This is significant as higher frequency harmonics generated along the data lines and from the external environment will affect the operation of the mobile electronics device.

The CM1405 offers ESD protection on all channels and is rated at ±15kV contact discharge per IEC61000-4-2 level 4 specification. The chip scale package provides up to 89% board space savings which in turn lowers the overall manufacturing costs.The CM1405 is manufactured using California Micro Devices’ advanced Centurion™ technology, which enables both superior EMI filter performance and a very high level of ESD protection.

The CM1405 pinout was configured to facilitate flow-through routing, simplifying PCB layout and optimizing filter performance. Chip scale packaging, by nature, also offers a very low inductance ground return path, further enhancing filter and ESD protection performance when compared to discrete EMI and ESD solutions.

The CM1405 gives design engineers another effective solution to solve their EMI filtering and ESD protection needs on the LCD interface, data ports and data lines. An effective EMI filter with ESD for a common 16-bit LCD display interface can be implemented with just two CM1405 devices vs. the current solution utilizing two 6 channel and one 4 channel EMI filter devices, providing significant savings in both cost and board space.

Features of the CM1405 include:

• Centurion™ process technology for effective EMI filter performance and robust ESD protection
• 8 channels of EMI Filtering with ESD protection
• Greater than 35dB of attenuation at 1GHz to reject unwanted high frequency signals
• Up to 89% board space savings versus discrete implementations
• Space-saving, low profile CSP form factor ideal for mobile applications
• Optional lead free finish and OptiGuard™ coating

Product Applications
The CM1405 family of devices is suitable for a number of applications where space as well as performance are considerations. These include:

• LCD data lines in mobile handsets
• EMI filtering and ESD protection for high-speed I/O ports
• EMI filtering for high-speed data lines
• Wireless handsets
• Cell phones
• Notebook computers
• PDAs / Handheld PCs

Sampling, Pricing and Availability
The CM1405 is currently sampling, and pricing starts at $0.57 each in 1,000 units. Volume production is scheduled for June 2004.