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

tuneProduct Options

Part Number Part Status Pkg. Type Carrier Type MOQ Buy Sample
Active SOICN Tube 980
Active SOICN Reel 2500
Active SOICN Reel 250


Title language Type Format File Size Date
Datasheets & Errata
star ISL12022 Datasheet Datasheet PDF 1.24 MB
User Guides & Manuals
Real Time Clock USB Evaluation Board User Guide Manual - Development Tools PDF 815 KB
Application Notes & White Papers
AN1549: Addressing Power Issues in Real Time Clock Applications Application Note PDF 302 KB
AN1400: ISL12022 RTC Accuracy Optimization Calibration Procedure Application Note PDF 426 KB
PCN12085 - 8l, 14l, 16l SOIC w/ Gold Bond Wire @ ATP as Alternate Assembly Site Product Change Notice PDF 152 KB
PCN11121 - Data Sheet Specification Change for Intersil Product ISL12022IBZ* Product Change Notice PDF 117 KB
Analog ICs Brochure 日本語 Brochure PDF 4.20 MB
PIN19028 - Q3 Cy 19 Price Increase Notice Price Increase Notice PDF 208 KB
IDT Clock Generation Overview 日本語 Overview PDF 1.83 MB


Title language Type Format File Size Date
RTC WIN8 Preinstallation Procedure Software & Tools - Other PDF 846 KB
Real Time Clock (RTC) Evaluation Installer for Windows 8 Library EXE 7.85 MB
Real Time Clock (RTC) Evaluation Installer for Windows 2000 Library EXE 1.62 MB
Real Time Clock (RTC) Evaluation Installer for Windows XP / Windows 7 Library EXE 3.02 MB

memoryBoards & Kits

Part Number Title Type Company
ISL120x-RTC-USB-Evaluation-System ISL120x Real Time Clock USB Evaluation System Evaluation Renesas

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