Ultra Low-Power 2.5µW CMOS Implementation of a Mixed Analog-Digital Wake-Up System Based on Frequency Analysis

An ultra low power acoustic wake-up detector based on high frequency signal analysis is presented in this paper. Focused on environmental or military Internet of Things (IoT) applications, it aims at detecting in real time the presence of specific animal species or drones for generating alerts and for triggering power consuming tasks such as high frequency signal recording only when needed.This wake-up detector continuously monitors the presence of specific frequencies in an analog acoustic signal, with a good frequency selectivity and a high frequency range detection capability. It is based on an ultra-low power analog frequency to voltage converter using a current-mirror, analog timers and synchronous comparators.Dedicated to long term stealth environmental or military surveys, a strong emphasis has been put on power consumption reduction in order to reduce batteries constraints. Its power consumption has been reduced to 2.5µW, leading to an autonomy of more than 28 years with a single coin cell CR2032 battery.