Circuit for classifying signals

A circuit for classification of analog input signals, comprising an analog memory component, such as a floating gate, used to store a threshold value; a threshold detection module used to determine whether the analog input signal exceeds the threshold value; a time delay module used to delay a processing of the analog signal; a time-amplitude window calculation module used to determine whether an amplitude of the analog input signal is between a lower limit and an upper limit of an amplitude window; and an output module indicating whether the amplitude of the analog signal is between the lower and the upper limit, wherein the indication is used to determine whether the analog input signal belongs to one of a plurality of analog signal classes. The classification is implemented in the analog domain, eliminating the need for sampling and digitizing the analog signal, consequently minimizing circuit area and power.