Special Hardware Concatenations for the Design of a High Dynamic Range ADC

摘要

An innovative method to design a high dynamic range ADC is described. The ADC was developed to acquire audio samples for community noise monitoring and pattern recognition with a sampling frequency of 22kSps and a dynamic range of 105dB (35dB_(SPL) to 140dB_(SPL)). By using low resolution ADCs, some analog amplification and filtering stages, and a concatenation algorithm, a good performance and cost efficient audio sampling module has been built for audio level calculations. In order to guarantee the signal readability a logarithmic legibility formula is introduced. A series of tests with different frequencies and dynamic ranges showed that the module can easily replace the current Sigma-Delta ADC boards.