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The CM1624, introduced by California Micro Devices, is an application-specific micro secure digital (microSD) interface protection filter suitable for mobile and computing devices. With the popularity of the microSD flash memory card, CMD asserts that its CM1624 not only curbs electrostatic discharge (ESD) damage and electromagnetic interference (EMI), but also offers good digital signal integrity.

The CM1624 has joined the Praetorian III product line and provides quality filter performance as well as minimal line capacitance, according to the company. Other features include integrated pull-up resistors that do not require extended circuitry on the handset printed circuit board (PCB) and also reduce costs, says CMD.

Sustaining clock frequencies as high as 96 MHz, the CM1624 also supports rise/fall times up to 5 ns and attenuation levels from 700 MHz to 3 GHz. The device’s pinout, designed for the microSD interface standard, offers six EMI suppression lines covered by IEC 61000-4-2, ±15 kV (contact) integrated ESD protection, as well as one through-package ESD protection line for the Vcc line.

MicroSD Interface Protection Filter Thwarts ESD And EMI

Two more ESD diodes have other capabilities, such as Card Detect, and 25-kΩ pull-up resistors can also recognize a memory card. The device also has a 20-pF 0-V dc capacitance specification, which reduces to less than 12 pF when it is operating.

The minimum capacitance level for EMI filters is suited for the microSD interface, says CMD, which provides more design latitude in printed-circuit board (PCB) routing and an easier design process for handset designers. A turnkey solution also complements the microSD interface, according to the company.

The CM1624-08DE comes in a RoHS-compatible microDFN16 package, with samples available at $0.16 each for orders of 3000. It is currently certified for mass production.