A 0.8-V, 55.1-dB DR, 100 Hz Low-Pass Filter with Low-Power PTAT for Bio-Medical Applications. Issue 3 (4th May 2022)

• Record Type: Journal Article
• Authors: Hanumantha Rao, G.; Rekha, S.
• Is Part Of: IETE journal of research. Volume 68:Issue 3(2022)
• Page Start: 1971
• Page End: 1981
• Publication Date: 2022-05-04
• Subjects: Bulk-driven transistor -- Low-frequency filters -- Low voltage and low-power transconductor -- PTAT current; Electronics -- Periodicals; Telecommunication -- Periodicals; Electronics; Telecommunication; Periodicals; 621.38
• DOI: 10.1080/03772063.2019.1682074
• Languages: English
• ISSNs: 0377-2063

Abstract

Abstract : This paper presents a power efficient transconductor-capacitor ( G m − C ) filter for front-end processing of bio-medical signals. A low voltage, low-power transconductor with improved output resistance is proposed. It offers a transconductance ( G m ) of 5.85 nS while operating at a supply voltage ( V d d ) of 0.8 V. Furthermore, a low-power Proportional to Absolute Temperature (PTAT) current reference circuit is designed to bias the transconductor and to make G m independent of temperature. It follows PTAT characteristics in the temperature range of −20 ∘ C to 70 ∘ C and is less sensitive to V d d variations. A second-order Butterworth low-pass filter (LPF) with a cutoff frequency of 100 Hz is implemented to validate the proposed transconductor and the PTAT circuit. The filter is designed in UMC 65 nm CMOS process and it takes an area of 0.065 mm 2 . While consuming a power of 47 nW, it offers a dynamic range (DR) of 55.1 dB. Figure-of-merit (FoM) of the filter is as low as 4.2 × 10 − 13 J, which is found to be on par with the filters reported in the literature.