Lower power wake-up device

Abstract

A circuit producing a wake-up signal with a frequency selective RF amplifier that produces an amplified RF output. An RF detector detects the RF output and produces a signal W indicative of the the RF output signal's presence. A threshold detector determines if the amplified output signal has reached a predetermined threshold and produces an output T. A clock signal is generated in response to the threshold detector output signal T. A data decoder logic circuit turns off the clock in the absence of an RF output signal for a time period and decodes the RF detector output W into a stream of output signals. A serial comparator compares a most recent stream of N output data from the data decoder logic with a stored reference to generate a wake-up signal that enables power to an electronic system. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.