A micropower class-AB CMOS log-domain filter for DECT applications

Author

Python, Dominique ; Enz, Christian C.

Author_Institution

Ukom Inc., San Jose, CA, USA

Volume

36

Issue

7

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

1067

Lastpage

1075

Abstract

This paper presents a micropower second-order low-pass filter using the log-domain principle and integrated in a 0.35-μm CMOS process. It has been designed as an antialiasing filter for a DECT transceiver with a 45-kHz nominal cutoff frequency. The circuit uses transistors biased in weak inversion without requiring separate wells. It operates at 1.5-V supply voltage and its current consumption is 8 μA in idle mode. The log-domain filter is implemented with an on-chip conditioner which allows class-AB operation. It can process input currents at 5 kHz that are 25 times larger than the 200-nA bias current. Measurements up to 500 times the bias current have been done, since at 1 kHz the input current is only limited by the supply voltage

Keywords

CMOS analogue integrated circuits; continuous time filters; cordless telephone systems; current-mode circuits; frequency response; low-pass filters; low-power electronics; transceivers; 1.5 V; DECT transceiver; antialiasing filter; class-AB CMOS log-domain filter; continuous time filters; current-mode linear integration; exponential transconductor; frequency response; micropower second-order low-pass filter; on-chip conditioner; weak inversion; Bipolar transistors; CMOS process; CMOS technology; Capacitors; Circuits; Energy consumption; Feedback; Low pass filters; MOSFETs; Voltage;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.933462

Filename

933462