Low power switched-resistor band-pass filter for neural recording channels in 130nm CMOS

Francesco Centurelli; Alessandro Fava; Pietro Monsurrò; Giuseppe Scotti; Pasquale Tommasino; Alessandro Trifiletti

doi:10.1016/j.heliyon.2020.e04723

Low power switched-resistor band-pass filter for neural recording channels in 130nm CMOS

Heliyon. 2020 Aug 24;6(8):e04723. doi: 10.1016/j.heliyon.2020.e04723. eCollection 2020 Aug.

Authors

Francesco Centurelli¹, Alessandro Fava¹, Pietro Monsurrò¹, Giuseppe Scotti¹, Pasquale Tommasino¹, Alessandro Trifiletti¹

Affiliation

¹ DIET (Dipartimento di Ingegneria dell'Informazione, Elettronica e Telecomunicazioni), University of Rome "La Sapienza", Italy.

Abstract

In this work, we present a low-power 2^nd order band-pass filter for neural recording applications. The central frequency of the passband is set to 375Hz and the quality factor to 5 to properly process the neural signals related to the onset of epileptic seizure, and to strongly attenuate all the out of band biological signals and electrical disturbances. The biquad filter is based on a fully differential Tow Thomas architecture in which high-valued resistors are implemented through switched high-resistivity polysilicon resistors. A supply voltage as low as 0.8V and MOS transistors operating in the sub-threshold region are exploited to achieve a power consumption as low as 170nW, when driving a 1pF load capacitance. The filter exhibits a tuning range of the resonance frequency from 200Hz to 400Hz, and an area footprint of only 0.021 mm². Very low power consumption and area occupation are key specifications for integrated, multiple-sensors, neural recording systems.

Keywords: Area efficient; Biomedical engineering; Brain-computer interface; Electrical engineering; Low-power; Neural recording; Neuroscience; Signal processing; Switched resistors filter; Very-large-scale integration; Wireless network.