Frequency-bandwidth-tunable powerline notch filter for biopotential acquisition systems

Author

Ma, C.-T. ; Mak, Pui-In ; Vai, Mang-I ; Mak, Peng-Un ; Pun, Sio-Hang ; Feng, Wenjie ; Martins, Rui P.

Author_Institution

Fac. of Sci. & Technol., Univ. of Macau

Volume

45

Issue

4

fYear

2009

Firstpage

197

Lastpage

199

Abstract

Presented is a novel powerline notch filter embeddable into a chopper-stabilised instrumentation amplifier for biopotential measurements. The frequency-translation property of the chopper enables the powerline notching to be indirectly implemented by two resonant zeros around the chopper frequency, resulting in substantial silicon area savings. Transistor-level implementation in 90 nm CMOS using a pseudo-LC circuit topology with Q-enhancement demonstrates 50 to 60 Hz frequency tunability, 25/41 dB powerline rejection at 5/30 Hz bandwidth, and 1000 relaxation of time constant under a 4 kHz chopper frequency.

Keywords

choppers (circuits); instrumentation amplifiers; network topology; notch filters; transistor circuits; CMOS; Q-enhancement; biopotential acquisition systems; chopper-stabilised instrumentation amplifier; frequency 4 kHz; frequency 50 Hz to 60 Hz; frequency tunability; frequency-bandwidth-tunable powerline notch filter; frequency-translation property; pseudo-LC circuit topology; transistor-level implementation;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:20093704

Filename

4784304