Dynamic Range Extension Using Multiple A/D Converters

Data acquisition boards with high bit-resolution ADCs such as 24 and 32 bits are relatively expensive as compared to standard 16, 12, and 8 bit systems. There is however a wide availability of low-cost boards with multi-channel AID conversion, usually at 8 or 12 bits per sample. The method described in this paper utilizes multi-channel conversion of the same signal, and then reconstructs a single signal at higher dynamic range. The method was motivated by the need to acquire raindrop impact sensor signals of wide amplitude variations using an ordinary portable computer. Even though this method may not be suitable for high-fidelity audio capture, without significant modifications, it provides a low-cost solution for instrumentation applications. ©2010 IEEE