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.


  • 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
  • Settable to the Second, Minute, Hour, Day of the Week, Day, or Month
  • Single Event or Pulse Interrupt Mode
  • Automatic Backup to Battery or Super Capacitor
  • Power Failure Detection
  • On-Chip Oscillator Compensation
  • 2 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 Ld MSOP and SOIC Packages
  • 8 Ld TDFN Package
  • Pb-Free Available (RoHS Compliant)




  • Utility Meters
  • HVAC Equipment
  • Audio/Video Components
  • Set-Top Box/Television
  • Modems
  • Network Routers, Hubs, Switches, Bridges
  • Cellular Infrastructure Equipment
  • Fixed Broadband Wireless Equipment
  • Pagers/PDA
  • POS Equipment
  • Test Meters/Fixtures
  • Office Automation (Copiers, Fax)
  • Home Appliances
  • Computer Products


Type Title Date
Datasheet PDF 1.06 MB
Brochure PDF 5.20 MB 日本語
Product Change Notice PDF 126 KB
End Of Life Notice PDF 603 KB
Price Increase Notice PDF 208 KB
Product Advisory PDF 363 KB
Product Change Notice PDF 152 KB
Product Change Notice PDF 135 KB
Other PDF 243 KB
Manual - Development Tools PDF 815 KB
Application Note PDF 302 KB
Manual - Development Tools PDF 443 KB
Application Note PDF 329 KB
Other PDF 266 KB
Other PDF 302 KB
Other PDF 264 KB
Manual - Development Tools PDF 913 KB
Other PDF 232 KB
18 items

Design & Development

Software & Tools

Software Downloads

Type Title Date
End Of Life Notice PDF 603 KB
Software & Tools - Other PDF 846 KB
Library EXE 7.85 MB
Library EXE 1.62 MB
Library EXE 3.02 MB
5 items

Boards & Kits

Boards & Kits