A High Dynamic Range CMOS Readout Chip for Electrochemical Sensors

This paper presents a high dynamic range, low-noise CMOS microinstrument chip for electrochemical sensors. It includes a programmable voltage generator, which provides the bias voltage for sensors and a high precision amperometric readout circuit. By using two readout channels, the detection range is boosted into +/- 1 nA-+/- 1 mA, which is beyond the input range of most sensor readout circuit. This chip could be integrated with various electrochemical sensors to form a lab-on-chip and achieve cost effective, in situ detection of different substances. Implemented in a 0.18-mu m CMOS process, the interface chip maintains a dynamic range of 120 dB with the 3.3 V single power supply. The functionality of the chip is verified by a prototype electrochemical sensor platform composed of this chip and a miniaturized sensor array.