EECOL_2006AUG06_ACC_AN_02.pdf

EECOL_2006AUG06_ACC_AN_02One Technology Way P.O. Box 9106 Norwood, MA 02062-9106 Tel: 781/329-4700 Fax: 781/326-8703 www.analog.com

AN-671 APPLICATION NOTE

Reducing RFI Rectification Errors in In-Amp Circuits
By Charles Kitchin, Lew Counts, and Moshe Gerstenhaber

INTRODUCTION Real-world applications must deal with an ever increasing amount of radio frequency interference (RFI). Of particular concern is where signal transmission lines are long and signal strength is low. This is the classic application for an in-amp since its inherent common-mode rejection allows it to extract weak differential signals riding on strong common-mode noise and interference. One potential problem that is frequently overlooked, however, is that of radio frequency rectification inside the in-amp. When strong RF interference is pr