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Real time clocks boost security, tamper detection

Milpitas, Calif.&#8212Intersil's ISL1219/21 real-time clocks are suited for time stamping single events such as the moment a warranty is voided by the removal of a cover, or recurring events such as the opening and closing of a security door. “The event detect and time stamp features in these ultra-small devices operate in both normal and battery mode,” said Rouben Gharagozian, marketing director for Intersil's Real-Time Clocks product group. “These micropower RTCs, with their enhanced security functionality, are uniquely suited for a variety of applications ranging from security, warranty monitoring, data collection and recording.”

These devices can time stamp an event by either issuing an output signal or by stopping the RTC registers from advancing at the moment the event occurs. The output signal contains the second, minute, hour, date, month and year that the triggering event occurred.

The ISL1219/21 offer two options for switching from normal power to battery backup power. All RTC functions except the I2 C bus are operational during battery backup mode unless disabled. The User SRAM is operational until battery power drops below 1.8 volts. The chip's integrated crystal compensation circuitry enables the use of a less expensive external crystal. The ISL1221 has a separate FOUT than the IRQ/FOUT in the ISL1219. The frequency output (FOUT) is programmable from 32.768 kHz to 1/32 Hz. It is used to clock the microcontroller in sleep mode, eliminating external crystal and further reducing the bill of materials.

Click here for additional information on the ISL1219 and here for the ISL1221. The ISL1219, in a 10-lead MSOP, is priced at $1.50 each in 1k quantitites. The ISL1221 is priced at $1.60. The company also provides evaluation boards for these devices.

Intersil , 1-888-INTERSIL, www.intersil.com

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