ISL1208IB8ZR5291

Description

The ISL1208 device is a low power real time clock with timing and crystal compensation, clock/calendar, power fail indicator, periodic or polled alarm, intelligent battery backup switching, and battery-backed user SRAM.

The oscillator uses an external, low-cost 32.768kHz crystal.

The real time clock tracks time with separate registers for hours, minutes, and seconds. The device has calendar registers for date, month, year and day of the week. The calendar is accurate through 2099, with automatic leap year correction.

The ISL1208's powerful 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.

The device also offers a backup power input pin. This VBAT pin allows the device to be backed up by battery or Super Capacitor with automatic switchover from VDD to VBAT. The entire ISL1208 device is fully operational from 2.0V to 5.5V and the clock/calendar portion of the device remains fully operational down to 1.8V (Standby Mode).

Features

   1. Real Time Clock/Calendar

   2. 15 Selectable Frequency Outputs

   3. Single Alarm

   4. Automatic Backup to Battery or Super Capacitor

   5. Power Failure Detection

   6. On-Chip Oscillator Compensation

   7. 2 Bytes Battery-Backed User SRAM

   8. I2C Interface

   9. 400nA Battery Supply Current

 10. Same Pin Out as ST M41Txx and Maxim DS13xx Devices

 11. Small Package Options

 12. Pb-Free Available (RoHS Compliant)

Applications

   1. Utility Meters

   2. HVAC Equipment

   3. Audio/Video Components

   4. Set-Top Box/Television

   5. Modems

   6. Network Routers, Hubs, Switches, Bridges

   7. Cellular Infrastructure Equipment

   8. Fixed Broadband Wireless Equipment

   9. Pagers/PDA

 10. POS Equipment

 11. Test Meters/Fixtures

 12. Office Automation (Copiers, Fax)

 13. Home Appliances

 14. Computer Products

 15. Other Industrial/Medical/Automotive

Pinout

The X1 and X2 pins are the input and output, respectively, of an inverting amplifier. An external 32.768kHz quartz crystal is used with the ISL1208 to supply a timebase for the real time clock. Internal compensation circuitry provides high accuracy over the operating temperature range from -40°C to +85°C. This oscillator compensation network can be used to calibrate the crystal timing accuracy over temperature either during manufacturing or with an external temperature sensor and microcontroller for active compensation. The device can also be driven directly from a 32.768kHz source at pin X1.