A real-time dynamic range expansion approach of multi-channel sampling system

Dynamic range (DR) is one of the most critical factors for evaluating a signal processing system. It is limited by all electronic components that signal passes through in the circuit, including the amplifier, analog-to-digital converter and etc. Based on the signal acquisition structure of synchronous sampling with multiple conditioning channels, this paper proposed a method to expand the DR of the system. The proposed method involves the iterative algorithm to calculate the gain and offset between different channels, the threshold voltage setting principles of channel switching, and the data combination approach. More importantly, it can easily be applied in programmable logic gate array in the real-time system. On the basis of ensuring system sensitivity, the input voltage range is increased by combining data from different channels, thereby the DR of the system is increased. The experimental results in the sampling board of the vibration and audio signal analyzer show that the method we discussed in this article has a significant effect on DR expansion in the sampling system.