Circuit Design Challenges of ADC for the Application in Multiple Physiological Parameters Detection System

Design challenges of ADC for the application in multiple physiological parameters detection system is discussed in this paper. Based on requirements in the physiological signal detection applications, design difficulties of these high precision Sigma-Delta ADCs, including multi-channel high effective resolution, ultra-low power and low channel mismatch, are analyzed with design tradeoff considerations. Results of a Sigma-Delta modulator for physiological parameters detection applications is given. The noise floor of the modulator is about -120dB, the SNR is 101.4dB, and ENOB is 16.55 bit, with the power consumption of 18 mW.