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

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)

Description

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 V_BAT > V_DD 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.

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