Nonlinear effects in pseudo differential OTAs with CMFB

Author

Mohieldin, Ahmed Nader ; Sánchez-Sinencio, Edgar ; Silva-Martínez, José

Author_Institution

Dept. of Electr. Eng., Texas A&M Univ., College Station, TX, USA

Volume

50

Issue

10

fYear

2003

Firstpage

762

Lastpage

770

Abstract

A general description of nonlinearities in pseudo differential operational transconductance amplifiers (OTA) with common-mode feedback (CMFB) is introduced. The effects of CMFB nonlinearities on the differential signals are evaluated and design tradeoffs including nonidealities are determined. A practical pseudo differential fully balanced fully symmetric OTA architecture with common-mode feedforward (CMFF) is used as a case study to probe the theory. The OTA has an inherent common-mode detector; hence, the CMFB circuit is efficiently implemented. The OTA is used to implement a 100-MHz fourth-order linear-phase OTA-C filter.

Keywords

CMOS analogue integrated circuits; active filters; differential amplifiers; feedback amplifiers; feedforward; nonlinear network analysis; operational amplifiers; 100 MHz; CMFB nonlinearities; CMFF; common-mode detector; common-mode feedback; common-mode feedforward; design tradeoffs; differential signals; fourth-order OTA-C filter; fully balanced OTA architecture; fully symmetric OTA architecture; linear-phase OTA-C filter; nonidealities; nonlinear effects; operational transconductance amplifiers; pseudo differential OTAs; Circuits; Detectors; Differential amplifiers; Filters; Impedance; Negative feedback; Operational amplifiers; Tail; Transconductance; Voltage;

fLanguage

English

Journal_Title

Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1057-7130

Type

jour

DOI

10.1109/TCSII.2003.818395

Filename

1237367