Signal activity-dependent analog-to-digital conversion

This paper presents an adaptive sampling approach in which analog signal samples are taken depending on its activity. By using the proposed approach the number of A/D conversions and therefore the resulting number of samples can be reduced during inactive periods of an analog signal. The proposed method is beneficial for ultra-low power circuits, e.g. sensors networks, where the nodes are idle most of the time, yet, in conventional sampling approach, the samples would be taken even if analog input signal is constant. Since all samples have to be transmitted at some point, this causes unnecessary energy consumption even if analog signal contains no useful information. Proposed sampling scheme allows achieving high data compression rate and reduction of energy consumption. Proposed implementation of signal activity-dependent sampling and power consumption analysis are presented in this paper. In addition, the circuit that tracks the variation of analog input signal is presented.