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AM08xx - Low Power Real-Time Clock


The Ambiq Micro AM08xx Low Power Real-Time Clock (RTC) 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 14nA in RC mode, 22nA in auto calibration mode, 55nA in XT mode), these are the first semiconductor products based on Ambiq Micro’s innovative SPOT™ (Subthreshold Power Optimized Technology) CMOS Platform.


  • Ultra-low supply current:
    • <14nA with RC oscillator
    • <22nA with RC oscillator and auto calibration
    • <55nA with crystal oscillator
  • Baseline timekeeping features:
    • 32 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 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
  • Enhanced I/O features:
    • Automatic switchover to VBAT
    • External interrupt monitor
    • Programmable brown out detection
    • Programmable analog voltage comparator
  • Up to 256 bytes of general purpose RAM
  • I²C (up to 400 kHz) or SPI (up to 2 MHz) serial interface
    • Supports 3-wire and 4-wire SPI
  • Operating Voltage 1.7-3.6 V
  • Clock and RAM retention voltage 1.5-3.6 V
  • Operating temperature –40 to 85 °C
  • 3 mm x 3 mm QFN-16 package
  • Also available in wafer form


  • Smart cards
  • Wireless sensors and IoT
  • Wearable health and fitness devices
  • Medical electronics
  • Utility meters
  • Data loggers
  • Appliances
  • Consumer electronics

AM08xx family summary

Part # Baseline Timekeeping Advanced Timekeeping Enhanced I/O Interface
XT Osc Number of GP Outputs RC Osc Calib/ Auto-calib Watch-dog RAM (B) VBAT Switch Ext Int
AM0805 4 256 I²C
AM0815 3 256 SPI

AM08xx Documentation



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