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ESD device gives eight-channel protection

Posted: 21 Aug 2009 ?? ?Print Version ?Bookmark and Share

Keywords:ESD? protection device? HDMI?

CM1238 ESD protection device

California Micro Devices (CMD) has extended its XtremeESD family that uses the PicoGuard XS architecture. The CM1238 ESD protection device provides eight channels of ESD protection that meet 15kV contact discharge and 20kV air discharge per the IEC61000-4-2 standard as well as the 100? differential impedance matching requirements of the HDMI 1.3a and DisplayPort digital video standards.

The CM1238 utilizes the second generation of the PicoGuard XS architecture based on a smaller diode design that enables enhanced signal integrity, smaller form factor and lower product cost while maintaining ESD protection at an industry leading 20kV level. It is suitable for digital TVs, LCDs, laptops, STBs and HD DVD recorders.

"CE designers face a broad array of design challenges in meeting consumer requirements for greater functionality and higher performance at ever decreasing prices," stated Kyle Baker, VP of marketing for CMD. "The CM1238 creates customer value by providing better performance and a smaller size at a lower price point."

PicoGuard XS architecture
The CM1238 incorporates the PicoGuard XS architecture that integrates inductors with the diodes to create fixed point impedance matching for high speed data lines. Traditionally, system designers must compensate for the capacitance of the ESD protection device by adding external inductance, eliminating capacitance under the signal traces near the ESD device, or both. These approaches add complexity and cost, and are PCB dependent, limiting the ability to use multiple board vendors. In many cases, this may not even be possible, particularly if the capacitance of the device is too high as is typical with existing 20kV ESD devices. The CM1238 eliminates the need for these measures, providing matched impedance with no external compensation or components required.

Delivering robust ESD protection requires much more than achieving compliance with industry standards. Standards define the level of ESD a protection solution can withstand before failing, but do not characterize the level of residual current that passes through the diode and reaches the device under protection. Therefore, it is important to select a device that not only complies with industry standards, but also ensures a low clamping voltage and low residual current. PicoGuard XS solutions feature peak clamping voltages up to 40 percent lower and peak residual currents between 15 percent to 40 percent lower than competing solutions.

The CM1238 provides protection for four pairs of differential channels, offering ESD protection to IEC61000-4-2 standard 15kV contact discharge and 20kV air discharge. The integration of inductors with the ESD diodes provides for improved ESD protection as well as outstanding signal integrity. The signal integrity is further enhanced as a result of the second generation PicoGuard XS architecture based on a smaller ESD diode structure that provides the same industry leading ESD performance, but with improved signal integrity. The reduced die size, together with a smaller package size, results in a lower cost compared to the first generation design.

The CM1238 is available in a 0.5mm pitch, 16-lead TDFN package (4mm x 1.7mm). Samples will be available in October with full production scheduled for December 2009. It is priced at $0.40 each at 1,000 units.

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