ISL12028A: Real Time Clock/Calendar with I2C Bus™ and EEPROM

The ISL12028 device is a low power real time clock with clock/calendar, power-fail indicator, clock output and crystal compensation, two periodic or polled alarms (CMOS output), intelligent battery backup switching, CPU Supervisor, integrated 512x8-bit EEPROM configured in 16 bytes per page.

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 ISL12028 and ISL12028A Power Control Settings are different. The ISL12028 uses the Legacy Mode Setting, and the ISL12028A uses the Standard Mode Setting. Applications that have VBAT > VDD will require only the ISL12028A. Please refer to "Power Control Operation" on page 14 for more details. Also, please refer to "I2C Communications During Battery Backup and LVR Operation" on page 25 for important details.

Key Features
  • Real Time Clock/Calendar
    • Tracks time in Hours, Minutes and Seconds
    • Day of the Week, Day, Month and Year
    • 3 Selectable Frequency Outputs
  • Two Non-Volatile Alarms
    • Settable on the Second, Minute, Hour, Day of the Week, Day, or Month
    • Repeat Mode (Periodic Interrupts)
  • Automatic Backup to Battery or SuperCap
    • Power Failure Detection
    • 800nA Battery Supply Current
  • On-Chip Oscillator Compensation
    • Internal Feedback Resistor and Compensation Capacitors
    • 64 Position Digitally Controlled Trim Capacitor
    • 6 Digital Frequency Adjustment Settings to ±30ppm
  • 512x8 Bits of EEPROM:
    • 16-Byte Page Write Mode (32 total pages)
    • 8 Modes of BlockLock™ Protection
    • Single Byte Write Capability
    • Data Retention: 50 years
    • Endurance: >2,000,000 Cycles Per Byte
  • CPU Supervisor Functions:
    • Power On Reset, Low Voltage Sense
    • Watchdog Timer (0.25s, 0.75s and 1.75s)
  • I2C Interface
    • 400kHz Data Transfer Rate
  • 14 Ld SOIC and 14 Ld TSSOP Packages
  • Pb-Free (RoHS Compliant)
Applications
  • Utility Meters
  • HVAC Equipment
  • Audio/Video Components
  • 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
  • Other Industrial/Medical/Automotive
Typical Diagram
Datasheets
TitleTypeUpdatedSizeOther Languages
ISL12027, ISL12027A DatasheetPDF14 Aug 2015768 KB
Software
TitleTypeUpdatedSizeOther Languages
Real Time Clock (RTC) Evaluation Installer for Windows XP / Windows 7EXE31 Oct 20143.02 MB
Real Time Clock (RTC) Evaluation Installer for Windows 2000EXE31 Oct 20141.62 MB
Real Time Clock (RTC) Evaluation Installer for Windows 8EXE31 Oct 20147.85 MB
User Guides
TitleTypeUpdatedSizeOther Languages
Real Time Clock USB Evaluation Board User GuidePDF12 May 2015487 KB
Miscellaneous
TitleTypeUpdatedSizeOther Languages
RTC WIN8 Preinstallation ProcedurePDF19 Nov 2014849 KB
Order Information
Part NumberPackage TypeWeight(g)PinsMSL RatingPeak Temp (°C)RoHS Status
ISL12028AIB27Z14 Ld SOIC0.13142260RoHS
ISL12028AIB27Z-T14 Ld SOIC T+R0.13142260RoHS
ISL12028AIV27Z14 Ld TSSOP0.054141260RoHS
ISL12028AIV27Z-T14 Ld TSSOP T+R0.054141260RoHS
ISL12027, ISL12027A Datasheet 14 Aug 2015
14 Ld SOIC HI-303
14 Ld TSSOP T+R ISL12023
ISL12028
Real Time Clock (RTC) Evaluation Installer for Windows XP / Windows 7 31 Oct 2014
Real Time Clock (RTC) Evaluation Installer for Windows 2000 31 Oct 2014
Real Time Clock (RTC) Evaluation Installer for Windows 8 31 Oct 2014
Real Time Clock USB Evaluation Board User Guide 12 May 2015
RTC WIN8 Preinstallation Procedure 19 Nov 2014