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California Micro Devices Launches microSD Interface Protection Filter for Mobile Handsets

Posted on: Tuesday, 7 July 2009, 08:30 CDT

MILPITAS, Calif., July 7 /PRNewswire-FirstCall/ -- California Micro Devices (Nasdaq: CAMD) today announced the CM1624, an application specific microSD (micro Secure Digital) interface protection filter for mobile and computing devices. The popular microSD flash memory card is increasingly used in portable devices to allow users to store or use data across different devices. The CM1624 protects the microSD memory card user interface against ESD (electrostatic discharge) damage to the card or to the hardware and suppresses EMI (electromagnetic interference) while providing excellent digital signal integrity. It is a member of the leading edge Praetorian III(R) product line and combines outstanding filter performance with minimal line capacitance. The CM1624 also features integrated pull-up resistors, eliminating the need for additional circuitry on the handset PCB (printed circuit board) and saving additional bill of materials cost.

(Photo: http://www.newscom.com/cgi-bin/prnh/20090707/SF41127)

Application Specific for the microSD Interface

Inductor based filter solutions offer the highest level of digital signal integrity available. The CM1624 can support clock frequencies up to 96 MHz, rise/fall times as fast at 5 nSec, and high levels of attenuation from 700 MHz to 3 GHz. The CM1624 pinout is optimized for the microSD interface standard and features 6 lines of EMI suppression with IEC 61000-4-2 +/-15kV (contact) integrated ESD protection, one line of through package ESD protection for the Vcc line, and two additional discrete ESD diodes for related functions such as Card Detect. Additionally, CMD has integrated 25k ohms pull-up resistors to help detect the presence of the memory card.

EMI Filtering on a Capacitive Budget

As process geometries used in manufacturing baseband and applications processors migrate to increasingly smaller feature sizes, system operating voltages are also becoming lower so that the amount of capacitive loading on the data lines has become a major concern for handset designers. The microSD interface specification allows for a total capacitive loading budget of 40 pF and traditional filter architectures consume too much of this tight design parameter. The CM1624 features a specification 0V DC capacitance of 20pF, and less than 12 pF at operating voltage - the lowest level of capacitance available in EMI filters designed for the microSD interface. The lower filter line capacitance affords handset designers greater design latitude with respect to PCB routing and improved ease of design.

CM1624-08DE Features

• Very low line capacitance (12 pF) at operating voltages
• Excellent signal integrity, rise times as fast as 5 nSec with 75 MHz clocks in a 50 ohms environment
• Industry leading >15 kV contact ESD protection across all ports
• Application specific, turnkey solution mated perfectly to the microSD interface, including integrated pull-up resistors

Packaging, Pricing and Availability

The CM1624-08DE is available in an industry standard, compact, RoHS compliant microDFN16 package. Samples and are available now and are priced at $0.16 each in quantities of 3000 units. The CM1624 is qualified for mass production now.

About California Micro Devices Corporation

California Micro Devices Corporation is a leading supplier of application specific analog and mixed signal semiconductor products for the mobile handset, high brightness LED (HBLED), digital consumer electronics and personal computer markets. Key product lines include protection devices for mobile handsets, HBLEDs, digital consumer electronics products and personal computers and mixed signal ICs for mobile handset displays. Detailed corporate and product information may be accessed at http://www.cmd.com.

The CMD logo and Praetorian III are registered trademarks of California Micro Devices Corporation. All other trademarks are property of their respective owners.

SOURCE California Micro Devices

Source: PR Newswire

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