Integrating data converters for picoampere currents from electrochemical transducers

Author

Breten, Madalina ; Lehmann, Torsten ; Braun, Edna

Author_Institution

Dept. of Inf. Technol., Tech. Univ. Denmark, Lyngby, Denmark

Volume

5

fYear

2000

fDate

2000

Firstpage

709

Abstract

This paper describes a current mode A/D converter designed for a maximum input current range of 5 nA and a resolution of the order of 1 pA. The converter is designed for a potentiostat for amperometric chemical sensors and provides a constant polarization voltage for the measuring electrode. A prototype chip using the dual slope conversion method has been fabricated in a 0.7 μm CMOS process. Experimental results from this converter are reported. Design problems and limitations of the converter are discussed and a new conversion technique providing a larger dynamic range and easy calibration is proposed

Keywords

CMOS integrated circuits; analogue-digital conversion; current-mode circuits; electrochemical sensors; 0.7 micron; CMOS chip; amperometric chemical sensor; calibration; current mode A/D converter; data converter; dual slope conversion; dynamic range; electrochemical transducer; potentiostat; Blood; CMOS process; Chemical sensors; Electrodes; Polarization; Prototypes; Switches; Transconductance; Transducers; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2000. Proceedings. ISCAS 2000 Geneva. The 2000 IEEE International Symposium on

Conference_Location

Geneva

Print_ISBN

0-7803-5482-6

Type

conf

DOI

10.1109/ISCAS.2000.857591

Filename

857591