Current-feedback source-degenerated CMOS transconductor with very high linearity

Author

Worapishet, A. ; Naphaphan, C.

Author_Institution

Mahanakorn Microelectron. Res. Centre, Mahanakorn Universiiy of Technol., Bangkok, Thailand

Volume

39

Issue

1

fYear

2003

Firstpage

17

Lastpage

18

Abstract

A highly linear current-feedback (CF) transconductor with resistive source-degeneration is developed in CMOS technology. It consists of a differential source follower cascaded with a classical source-degenerated transconductor with its drain current fed back to modulate the bias of the source follower for nonlinearity cancellation, yielding an overall linear transfer function in the circuit. Designed using a 0.35 μm CMOS process for a continuous-time delta-sigma application, the CF transconductor achieves a total harmonic distortion better than -80 dB up to 1 MHz for a 0.8 V input differential voltage while the supply voltage is 2.5 V and the power consumption is 3.4 mW.

Keywords

CMOS integrated circuits; analogue-digital conversion; cascade networks; circuit feedback; continuous time filters; delta-sigma modulation; harmonic distortion; integrated circuit layout; network topology; 0.35 micron; 0.8 V; 1 MHz; 2.5 V; 3.4 mW; CMOS technology; continuous-time delta-sigma application; current-feedback source-degenerated CMOS transconductor; differential source follower; drain current feedback; highly linear current-feedback transconductor; input differential voltage; linear transfer function; nonlinearity cancellation; power consumption; resistive source-degeneration; source follower bias modulation; supply voltage; total harmonic distortion; very high linearity;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el:20030050

Filename

1182322