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.
|Title of host publication||The 2000 IEEE International Symposium on Circuits and Systems : Proceedings|
|Place of Publication||Geneva|
|Publication status||Published - 2000|
|Event||2000 IEEE International Symposium on Circuits and Systems - Geneva, Switzerland|
Duration: 28 May 2000 → 31 May 2000
|Conference||2000 IEEE International Symposium on Circuits and Systems|
|Period||28/05/2000 → 31/05/2000|