Adafruit S-35710 Low-Power Wake Up Timer Breakout - STEMMA QT / Qwiic

The Adafruit S-35710 Wake Up Timer is a low power 'watchdog timer' chip that can be programmed to alert with a digitally-configurable alarm from 1 second up to 194 days, thanks to a 24-bit second counter. It's a useful alternative to a real time clock or internal sleep timer, ideal for ultra-low-power projects wanting a separate chip to handle time-keeping and alarms.

Usage is simple: On I2C write of the timer register, the chip starts counting from 0 seconds and the OUT pin goes high. When the count matches the timer register, the OUT pin goes low. It draws only 0.2uA of current, offering an extremely low power consumption.

The output is open-drain. A switch allows inverting the output signal via an N-channel FET, changing the polarity. Note that on power-up the OUT line is low by default, so it is not suitable as a low-power sleep manager that resets on power-up, but it can be useful for signaling after a long delay or complex power management schemes.

This breakout is designed in the STEMMA QT form factor with connectors compatible with SparkFun Qwiic. This enables solderless connections and easy chaining with other STEMMA QT or Qwiic sensors and accessories.

• Digitally configurable alarm from 1 second to 194 days via 24-bit counter
• Ultra low power consumption: 0.2uA
• Open-drain output with polarity invert switch
• STEMMA QT / Qwiic compatible connectors for easy I2C connectivity
• Compact and easy to integrate in power management and timing projects