Date: 09/07/2009

CMD's new protection filter for microSD interfaces

California Micro Devices (CMD) has released a new interface protection filter specifically suited for microSD interfaces. The CM1624 combines of EMI filtering, line termination and TVS diodes in a single UDFN package, ideal for protecting these interfaces in cellular phones and other portable devices. The CM1624 uses innovative inductor-based filter design based on Praetorian III coupled inductor architecture.

Praetorian III technology uses two layer coupled inductor architecture. By utilizing this structure, Praetorian III devices provide large value inductances, which permits the use of lower capacitance Zener diodes, resulting in improved filter characteristics compared to traditional filter solutions.

Praetorian III coupled inductor advantages:
Steeper attenuation curves at lower frequencies ( RF Performance Curve )
Low total line capacitance <12pf at operating voltages
Supports clock frequencies up to 96MHz
Cut off frequency at 300MHz typical
Broad stop band starting in 700MHz band up to 3 GHz
Minimal insertion loss ( <-1.5dB typical)
Rise and fall times less than 5ns
Highest level of ESD protection (up to ±15kV per IEC 61000-4-2 Level 4, contact discharge)

The CM1624 offers through package ESD protection circuit for VCC and 2 discrete diodes for other function such as Card Detect (CD). Each of the microSD interface lines feature a 25kO pull-up resistor to assist in detecting the presence of a memory card.
CM1624 Applications
MicroSD / T-Flash interfaces
MMC interfaces
CDMA, GSM, 3G cell phones

Availability: Now in samples

Price: Each $0.16 each in quantities of 3000 units.

For details visit: www.cmd.com