AM18x5 ultra-low power RTC with advanced power management

AM18x5 ultra-low power RTC with advanced power management

can be shipped within 5 days

The Ambiq Micro AM18xx Low Power Real-Time Clock (RTC) family provides a groundbreaking combination of ultra-low power coupled with a highly sophisticated feature set optimized for system-level power management. 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.

Advanced power management features includes an integrated power switch and a sophisticated system sleep manager with counter, timer, alarm, and interrupt capabilities that allows the AM18xx to be used as a complete system-level power manager.

Also available in wafer form


  • 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
  • Advanced power management features:
    • Integrated <1Ω power switch for off-chip components such as a host MCU, radio, sensor, etc.
    • System sleep manager for managing host processor wake/sleep states
    • External interrupt monitor
    • External reset signal monitor
    • Reset output generator
    • Automatic switchover to VBAT
    • Supercapacitor trickle charger with programmable charging current
    • 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

AM18xx family summary

Part # Baseline Timekeeping Advanced Timekeeping Power Management Interface
XT Osc Number of GP Outputs RC Osc Calib/ Auto-calib Watch-dog RAM (B) VBAT Switch Reset Mgmt Ext Int Power Switch and Sleep FSM
AM1805 4 256 I²C
AM1815 3 256 SPI


Product variations
Interface: I²C
0.66 *
Interface: SPI
0.66 *
* Prices plus VAT, plus delivery
Browse this category: Low Power Real-Time Clock