A Novel Full Differential Feedforward Fourth-Order Bandpass Sigma-Delta Modulator

Jia-Jun Zhou, Hong-Lin Xu, Rui Zhang, Xiao-Wei Liuª¤

(1. Micro Electromechanical System Center, Harbin Institute of Technology, Harbin 150001, China;ª¤2. Key Laboratory of Micro-Systems and Micro-Structures Manufacturing, Ministry of Education, Harbin 150001, China)ª¤ª¤ª¤



Abstract:

In this paper, in order to reduce power consumption and chip area, as well as to improve the performance of the bandpass sigma-delta modulator, a novel full differential feedforward fourth-order bandpass sigma-delta modulator was proposed. It used a resonator based on Salo architecture, which employed double-sampling and double-delay technique. The results show that the proposed modulator can achieve lower power consumption and a lower capacitive load than the conventional bandpass modulators on the platform of Simulink. The circuit is implemented with TSMC0.18 ¦Ìm CMOS process and operates at a sampling frequency of 20 MHz, 80 MHz effective sampling frequency. Furthermore, it consumes 21.2 mW from a 1.8 V supply. The simulated peak signal-to-noise ratio (SNR) is 85.9 dB and the dynamic range (DR) is 91 dB with 200 kHz bandwidth.ª¤

Key words:  bandpass  Sigma-Delta  modulator  double-samplingª¤

DOI£º10.11916/j.issn.1005-9113.2013.05.022

Clc Number:TN47

Fund: