Dynamic-range analysis and maximization of micropower Gm-C bandpass filters by adaptive biasing

Author

Arfin, Scott K. ; Mandal, Soumyajit ; Sarpeshkar, Rahul

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., Massachusetts Inst. of Technol., Cambridge, MA, USA

fYear

2009

fDate

24-27 May 2009

Firstpage

2954

Lastpage

2957

Abstract

We analyze and present an input gain-varying scheme for maximizing dynamic range in a well-known G_m-C bandpass filter by both minimizing noise for small input signals, and by achieving balanced swing levels at all filter nodes for large input signals. A micropower bandpass filter suitable for use in cochlear implants and other power-constrained biomedical applications was implemented and tested in subthreshold CMOS. At a center frequency of 1.4 kHz and quality factor of 4, the filter has 70 dB of dynamic range (57 dB maximum SNR, 2.5% total harmonic distortion (THD)) and consumes 2.55 muW of power.

Keywords

CMOS integrated circuits; band-pass filters; low-power electronics; THD; adaptive biasing; cochlear implants; dynamic-range analysis; frequency 1.4 kHz; micropower G_m-C bandpass filters; power 2.55 muW; power-constrained biomedical applications; subthreshold CMOS; total harmonic distortion; Band pass filters; Cochlear implants; Dynamic range; Frequency; Noise level; Power harmonic filters; Q factor; Signal analysis; Testing; Total harmonic distortion;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2009. ISCAS 2009. IEEE International Symposium on

Conference_Location

Taipei

Print_ISBN

978-1-4244-3827-3

Electronic_ISBN

978-1-4244-3828-0

Type

conf

DOI

10.1109/ISCAS.2009.5118422

Filename

5118422