Abstract:On-chip analog filter is a key part for integrated circuits preprocessing physiological signals, which influences the quality of signals acquired. Since the frequency of the physiological signals is of ultra-low range, the on-chip large capacitance in the analog filter is the key problem to be solved immediately. The paper summaries the recent progress of the capacitance multiplier development, such as current mode capacitance multiplier, voltage mode capacitance multiplier, capacitance multiplier based on current-to-voltage converter and unbalanced capacitance multiplier, and then analyzes the key technology. Finally the paper looks into the future of the capacitance multiplying circuits.
[1] Li Y, Poon C C Y, Zhang Y T. Analog integrated circuits design for processing physiological signals[J]. IEEE Reviews in Biomedical Engineering, 2010, 3:93-105.
[2] 李严. 可穿戴式医疗芯片研究进展[J]. 科技导报, 2017, 35(2):33-40.
[3] 李严, 张元亭. 一种用于可穿戴式生理参数检测的集成电路[J]. 电子技术应用, 2016, 42(11):18-21.
[4] 李严. 一种适用于生理信号的OTA-C滤波器[J]. 微电子学, 2017, 47(4):510-513.
[5] Silva-Martinez J, Vazquez-Gonzalez A. Impedance scalers for IC active filters[C]//IEEE International Symposium on Circuits and Systems, Monterey, CA, 1998:151-154.
[6] Silva-Martinez J, Solis-Bustos S. Design considerations for high performance very low frequency filters[C]//Proceedings of the 1999 IEEE International Symposium Circuits and Systems, Orlando, FL, 1999:648-651.
[7] Solis-Bustos S, Silva-Martínez J, Maloberti F, et al. A 60 dB dynamic-range CMOS sixth-order 2.4 Hz low-pass filter for medical applications[J]. IEEE Transactions on Circuits and System-II, 2000, 47(12):1391-1398.
[8] Hsu C L, Ho M H, Wu Y K, et al. Design of low-frequency low-pass filters for biomedical applications[C]//IEEE Asia Pacific Conference on Circuits and Systems, Singapore. 2006:690-695.
[9] Germanovix W, Bonizzoni E, Maloberti F. Capacitance super multiplier for sub-hertz low-pass integrated filters[J]. IEEE Transactions on Circuits and Systems-II:Express Briefs, 2018, 65(3):301-305.
[10] Padilla-Cantoya I. Capacitor multiplier with wide dynamic range and large multiplication factor for filter applications[J]. IEEE Transactions on Circuits and Systems-II:Express Briefs, 2013, 60(3):152-156.
[11] Li Y, Wong A K Y, Zhang Y T. A Fully-integrated transimpedance amplifier for photoplethysmographic signal processing with two-stage miller capacitance multiplier[J]. Electronics Letters, 2010, 46(11):745-746.
[12] Padilla-Cantoya I, Furth P M. Enhanced grounded capacitor multiplier and its floating implementation for analog filters[J]. IEEE Transactions on Circuits and Systems-II:Express Briefs, 2015, 62(10):962-966.
[13] Brînzoi P, Cracan A, Cojan N. A new approach in designing electrically controlled capacitance multipliers[C]//International Symposium on Signals, Circuits and Systems, Iaşi, 2011:1-4.
[14] Bonteanu G. A wide range fine tuning capacitance multiplier[C]//IEEE 23rd International Symposium for Design and Technology in Electronic Packaging (SIITME), Constanța, Romania, 2017:122-125.