Title :
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
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;
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
DOI :
10.1109/ISCAS.2000.857591
