A Low Power, High-Accuracy, 1-V CMOS Potentiostat for Amperometric Sensors

Abstract

In this paper, a three-electrode, low power potentiostat for biomedical and chemical sensor applications is implemented. A modified regulated cascode current mirror employing split length technique is used as an interface between the potentiostat circuit and sensor electrode, resulting in better performances in terms of input and output impedances, linearity, bandwidth and gain. The potentiostat is implemented for both single-ended and fully differential configurations using UMC 65 nm CMOS technology, having chip areas of 0.014 mm2 and 0.086 mm2 , respectively. The circuit results in detection of reduction-oxidation (redox) current of 50 nA to 4.8 µA and 0.1 nA to 7.2 µA, while consuming power of (0.06 to 3) µW and (1.2 to 18) µW for single-ended and differential potentiostat configurations, respectively. Differential potentiostat results in better linearity and dynamic range than single ended.