Clock-Less Analog-to-Digital Converter

This article presents a new clock-less analog-to-digital converter (ADC) based on a full analog signal processing. The main innovative feature of the proposed ADC is that, for a sampled input signal, a cascade of identical stages may operate without timing signal (clock) with its analog processing independent of the output digital signal’s generation. Clock-less converters are used in the medical area, in control equipment, and portable equipment of low consumption. In this work, time of conversion of 0.5 μs was obtained by simulations with spice macromodels, for a converter of 8 bits resolution, with 8 mW consumption. The Signal-to-Noise Ratio (SNR) reaches 60 dB. Index Terms – Analog-to-Digital Converter (ADC), Analog Signal Processing, Asynchronous, Analog, Irregular Sampling, CMOS.