Design and implementation of a low-pass filter for microsensor signal processing

• Published in: Journal of semiconductors Vol. 31; no. 12; pp. 101 - 104
• Main Authors: Wang, Zhuping (竹萍 王), Zhong, Shun'an (顺安 仲), Ding, Yingtao (英涛 丁), Wang, Xiaoqing (晓清 王)
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.12.2010
• Subjects: CMOS技术; 低通滤波器; 信号处理系统; 开关电容滤波器; 微传感器; 数字转换器; 精度设计; 预过滤器
• ISSN: 1674-4926
• DOI: 10.1088/1674-4926/31/12/125002

A novel low-pass filter that consists of a switched capacitor filter （SCF） and its antialiasing prefilter and smoothing postfilter is proposed for a microsensor signal processing system, which is used in separation point detection on the surface of micro air vehicles. In the system, the filter is not only applied to finish the function of filtering but also used as the front end antialiasing filter of the over sampling analog-to-digital converter. This proposed implementation mostly relies on the design of a high-precision SCF employing a correlated double sampling technique and optimisation switches. Simultaneously, the multiple-loop feedback low pass filter with good high frequency attenuation characteristics is applied as the pre- and postfilter. The design is implemented in the Central Semiconductor Manufacturing Corporation （CSMC） 0.5 μm double-poly three-metal （2P3M） 3 chip die area occupies only 0.39 mm2 and dissipatesl.53 mW. 3 V CMOS technology, with satisfactory results, The