Analysis and design of a multi-bit sigma-delta modulator for chromatography application

This paper presents the parameters design, modeling and performance analysis of the Sigma-Delta Modulator (SDM) for chromatography application. Chromatograph instruments often have rigid requirements to the output analog signal in signal processing. In order to ensure the high resolution, it requires not only the noise is very small and the signal distortion is not existence. The rate of signal to noise of SDM usually should be higher than 106dB. Specially, the frequency of chromatography signal is very low, often lower than 2Hz. It is different from other applications. In this paper, the main parameters of SDM for chromatography are designed and the topology of modulator is optimized. Finally, simulations are conducted by simulink modeling. Results show that the proposed SDM is stable and suitable for chromatography application.