SOURCE: Intersil

September 11, 2006 06:00 ET

Intersil's Real-Time Clocks Compensate for Drift Over Time and Temperature

Intersil's ISL1218/20 Feature Timing and Crystal Compensation, I2C Interface, Power Fail Indicator, Intelligent Battery Backup Switching, Periodic or Polled Alarm and 8 Bytes of Battery-Backed User SRAM

MILPITAS, CA -- (MARKET WIRE) -- September 11, 2006 -- Intersil Corporation (NASDAQ: ISIL), a world leader in the design and manufacture of high-performance analog semiconductors, today introduced two new micropower real-time clock/calendar devices. The ISL1218 and ISL1220 with on-chip timing and crystal compensation deliver accurate timekeeping with very low power dissipation.

The accuracy of an RTC typically depends on the frequency of the external crystal that is used as the time basis. However, the ISL1218/20 allow designers to adjust integrated analog and digital timing registers to trim the internal oscillator for initial accuracy.

"The designer can adjust the on-chip oscillator through I2C digital interface," said Rouben Gharagozian, marketing director for Intersil's Timing products group. "The analog trimming register calibrates on-chip digital capacitors and the digital timing register adjusts the timing counter. This finally makes using a lower-cost, 32.768kHz quartz crystal a practical and accurate option."

Cost and Space Savings

The ISL1218/20 also feature power failure detection, periodic or polled alarm, intelligent battery backup switching, 8 bytes of battery backed SRAM (static random access memory) and Intersil's battery-saving InterSeal™ technology to prevent initial battery drain prior to first use. The ISL1220 has a separate FOUT pin to allow clocking of the micro through RTC while having a separate alarm pin. The ISL1218 is housed in an 8-lead SOIC or MSOP package, and the ISL1220 is housed in a 10-lead MSOP package. Small packaging and integrated functionality combine to save designers cost and board space.

Intersil's Trademarked InterSeal™ Battery-Saving Feature

Intersil's InterSeal™ Battery Saver prevents initial battery current drain before the devices are first used. For example, battery-backed RTCs are commonly packaged on a board with a battery connected. In order to preserve battery life, these devices will not draw any power from the battery source until after the device is first powered up from the VDD source.

Periodic or Polled Alarm

The alarm can be set to any clock/calendar value for a match (for example: every minute, every Tuesday or at 5:23 AM on March 21). The alarm status is available by checking the Status Register, or the device can be configured to provide a hardware interrupt via the IRQ pin. There is a repeat mode for the alarm allowing a periodic interrupt every minute, every hour, every day, etc.

Key Features

--  Real-time clock/calendar
    --  Tracks time in hours, minutes, and seconds
    --   Day of the week, day, month, and year
--  15 selectable frequency outputs
--  Single alarm
    --  Programmable to the second, minute, hour, day of the week, day or
    --  Single event or pulse interrupt mode
--  Automatic backup to battery or super cap
--  Power failure detection
--  On-chip oscillator compensation
--  8 bytes battery-backed user SRAM
--  I2C interface
    --  400kHz data transfer rate
--  400nA battery supply current
--  Same pin out as ST M41Txx and Maxim DS13xx devices
--  Small package options
    --  8- and 10-lead MSOP and SOIC packages
--  Pb-free plus anneal available (RoHS compliant)

Target Applications

--  Industrial, including power meters, control units, security systems,
    ATMs, cameras, vending machines and electronic door openers
--  Medical, including portable medical instruments, defibrillators and
    glucose meters
--  Handheld units, such as point-of-sale terminals and scanners
About Intersil's Timing Circuits

Intersil has a broad portfolio of timing control products that offers a selection of industry-standard quartz- and RC-based timing/oscillator ICs along with real-time clocks. Timing circuits provide clock pulsing and synchronization in digital systems as well as pulse modulation circuits. Real-time clocks provide actual time in a digital format for clock displays, rate measurement, computers and a variety of consumer and industrial systems. This portfolio of devices also features InterSeal™ battery saver technology, programmable temperature compensation, and other integrated functions, such as programmable alarms, power-on reset and watchdog timer, EEPROM/SRAM for control and storage use (16 to 256kb), and a clock divider to provide a clock to other circuits. To learn more about Intersil's timing circuits portfolio, visit the Timing Circuits page at

Packaging, Pricing and Availability

The ISL1218 is available now in 8-lead SOIC and MSOP packages, with prices starting at $1.27 each. The ISL1220 is offered in a 10-lead MSOP and is priced at $1.14. All pricing is in 1,000-unit quantities. Intersil also provides evaluation boards for the new I2C real-time clock family. More information on the ISL1218 is available at,1477,ISL1218,0.html and more information on the ISL1220 is available at,1477,ISL1220,00.html.

Note to editors: To view a high-resolution downloadable photo of the ISL1218/20, visit Intersil's photo room at:

About Intersil

Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products address some of the industry's fastest growing markets such as flat panel displays, cell phones, handheld products and notebook computing. Intersil's product families address both power management and analog signal processing functions. Intersil products include ICs for battery management; hot-swap and hot-plug controllers; linear regulators; supervisory ICs; switching DC/DC regulators; power MOSFET drivers; optical storage laser diode drivers; DSL line drivers; video and high-performance operational amplifiers; data converters; interface ICs; analog switches and multiplexers; crosspoint switches; voice-over-IP devices; and ICs for military, space and radiation-hardened applications. For more information about Intersil or to find out how to become a member of our winning team, visit the Company's web site and career page at

InterSeal is a trademark of Intersil Americas, Inc. All other brands or product names are trademarks or registered trademarks of their respective holders.

Contact Information

  • Media Contact
    Kim Fehrt
    Public Relations Manager
    Intersil Corporation
    (408) 546-3566
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