Description
The ABRACON AB18XX Real Time Clock with Power Management family provides a groundbreaking combination of ultra-low power coupled with a highly sophisticated feature set. With power requirements significantly lower than any other industry RTC (as low as 14 nA), these are the first semiconductors based on innovative SPOTTM (Subthreshold Power Optimized Technology) CMOS platform.

Features
• Ultra-low supply current (all at 3V):
    - 14 nA with RC oscillator
    - 22 nA with RC oscillator and Autocalibration
    - 55 nA with crystal oscillator
• Baseline timekeeping features:
    - 32.768 kHz crystal oscillator with integrated load capacitor/resistor
    - Counters for hundredths, seconds, minutes, hours, date, month, year, century, and weekday
    - Alarm capability on all counters
    - Programmable output clock generation (32.768 kHz to 1 year)
    - Countdown timer with repeat function
    - Automatic leap year calculation
• Advanced timekeeping features:
    - Integrated power optimized RC oscillator
    - Advanced crystal calibration to ± 2 ppm
    - Advanced RC calibration to ± 16 ppm
    - Automatic calibration of RC oscillator to crystal oscillator
    - Watchdog timer with hardware reset
    - Up to 256 bytes of general purpose RAM
• Power management features:
    - Integrated ~1Ω power switch for off-chip components such as a host MCU
    - System sleep manager for managing host processor wake/sleep states
    - External reset signal monitor
    - Reset output generator
    - Supercapacitor trickle charger with programmable charging current
    - Automatic switchover to VBAT
    - External interrupt monitor
    - Programmable low battery detection threshold
    - Programmable analog voltage comparator
• I2C (up to 400 kHz) and 3-wire or 4-wire SPI (up to 2 MHz) serial interfaces available
• Operating voltage 1.5-3.6 V
• Clock and RAM retention voltage 1.5-3.6 V
• Operating temperature –40 to 85 °C
• All inputs include Schmitt Triggers
• 3x3 mm QFN-16 package

Applications
• Smart cards
• Wireless sensors and tags
• Medical electronics
• Utility meters
• Data loggers
• Appliances
• Handsets
• Consumer electronics
• Communications equipment