The ISL12022 device is a low power real time clock with an embedded Temp sensor for oscillator compensation, clock/calendar, power fail, low battery monitor, brownout indicator, single periodic or polled alarms, intelligent battery-backup switching, Battery Reseal™ function and 128 bytes of 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. Daylight Savings time adjustment is done automatically, using parameters entered by the user. Power fail and battery monitors offer user-selectable trip levels. A time stamp function records the time and date of switchover from VDD to VBAT power, and also from VBAT to VDD power.


  • Real Time Clock/Calendar - Tracks Time in Hours, Minutes and Seconds; Day of the Week, Day, Month, and Year
  • On-chip Oscillator Compensation Over the Operating Temperature Range - ±5ppm Over -40°C to +85°C
  • Customer Programmable Day Light Saving Time
  • 15 Selectable Frequency Outputs
  • 1 Alarm settable to the Second, Minute, Hour, Day of the Week, Day, or Month; Single Event or Pulse Interrupt Mode
  • Battery Reseal™ Function to Extend Battery Shelf Life
  • Automatic Backup to Battery or Super Capacitor
  • Oscillator Failure Detection
  • Time Stamp for First VDD to VBAT, and Last VBAT to VDD
  • 128 Bytes Battery-Backed User SRAM
  • I2C Bus™
  • 1µA Typical Battery Current
  • Pb-Free (RoHS Compliant)




  • Utility Meters
  • POS Equipment
  • Medical Devices
  • Security Systems
  • Vending Machines
  • White Goods
  • Printers and Copiers


Type Title Date
Datasheet PDF 1.24 MB
Brochure PDF 5.20 MB 日本語
Price Increase Notice PDF 208 KB
Product Change Notice PDF 152 KB
Product Change Notice PDF 117 KB
Manual - Development Tools PDF 815 KB
Application Note PDF 302 KB
Application Note PDF 426 KB
8 items

Design & Development

Software & Tools

Software Downloads

Type Title Date
Software & Tools - Other PDF 846 KB
Library EXE 7.85 MB
Library EXE 1.62 MB
Library EXE 3.02 MB
4 items

Boards & Kits

Boards & Kits