10-Bit 200 kHz/8-Channel Incremental ADC for Biosensor Applications

Abstract

In this paper, a second-order discrete-time (DT) modulator for 8-channel Incremental Sigma-Delta analog-to-digital converter (IADC) is presented for biomedical applications ranging from kHz. The proposed DT modulator with input bandwidth of 25[Formula: see text]kHz on each channel is sampled at 51.2[Formula: see text]MHz, with oversampling ratio of 128 implemented at 180[Formula: see text]nm technology. The proposed IADC has high resolution, multichannel A/D conversion, simple architecture, low offset, low gain error and low area over the standard ADCs available. Measured results show that the SNR, DR, ENOB, power consumption and chip area of the proposed IADC are 63.9[Formula: see text]dB, 62.2[Formula: see text]dB, 10.11 bits, 0.832[Formula: see text]mW and 0.032[Formula: see text]mm2, respectively, at 1.8V power supply. For testing purpose, the noncoherent sampling is done to get the FFT plot of the output signal. For further validation, the proposed second-order IADC was also designed and compared in MATLAB/Simulink.