An 8.2-μW 0.14-mm<SUP>2</SUP> 16-Channel CDMA-Like Capacitance-to-Digital Converter

作     者：Luo, Yuxuan Li, Yida Thean, Aaron Voon-Yew Heng, Chun-Huat 

作者机构：Natl Univ Singapore Dept Elect & Comp Engn Singapore 119077 Singapore 

出 版 物：《IEEE JOURNAL OF SOLID-STATE CIRCUITS》 (IEEE固体电路杂志)

年 卷 期：2020年第55卷第5期

页      面：1361-1373页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 

基　　金：NUS Hybrid-Integrated Flexible (Stretchable) Electronic Systems Program (HiFES) program, through the LAkSA: Large-Area Skin-Conformable Natural Interfaces in Self-Aligning Polymer Platform Project [R263-501-011-133] Singapore's National Research Foundation [NRF-RSS2015-003] E6Nanofab, National University of Singapore 

主　　题：Capacitance-to-digital converter (CDC) capacitive sensor array electronic skin (e-skin) multi-channel sensor interface circuits pressure sensors 

摘      要：This article presents a multi-channel capacitance-todigital converter (CDC) circuits using the continuous-time Walsh coding multiplexing. The proposed circuits modulate the input capacitive sensors with orthogonal codes, enable simultaneous read-in of 16 capacitive sensors, and provide the combined 16 digitized outputs in a single conversion. By correlating 16 successive digitized outputs with the corresponding orthogonal codes in post-processing, the 16 capacitive channels can then be demodulated separately. The proposed continuous-time Walsh coding modulation preserves temporal information with minimum circuitry duplication and bandwidth requirement. This chip is fabricated in 130-nm CMOS technology and occupies an area of 0.14 mm2. With a reference clock of 4 MHz, the proposed multi-channel CDC achieves 11.4 ENOB with an average conversion time of 482 mu s. It consumes 0.51 mu W/channel and achieves an FoM of 87 fJ/conversion step.