A low power, highly stabilized three electrode potentiostat for biomedical implantable systems

• Published in: Analog integrated circuits and signal processing 2015-05, Vol.83 (2), p.217-229
• Main Authors: Roknsharifi, Melika, Islam, Syed Kamrul, Zhu, Kai, Mahbub, Ifana
• Format: Article
• Language: English
• Subjects: Circuits and Systems; Electrical Engineering; Electrodes; Engineering; Glucose; Operational amplifiers; Potentiostats; Power consumption; Sensors; Signal,Image and Speech Processing; Stability
• ISSN: 0925-1030; 1573-1979
• DOI: 10.1007/s10470-015-0524-0

This paper presents a low-power three-electrode potentiostat for biomedical implantable glucose sensor applications. Low power consumption is one of the most important criteria for a wireless implantable biomedical sensor. Therefore the proposed potentiostat is designed to minimize power consumption of the sensor while maximizing the stability of the system by achieving high phase margin. The transistors in the operational transconductance amplifier (OTA) block of the potentiostat are designed to operate in weak inversion region to meet the low-power design objective. Analysis and calculation of the position of the poles and zeros of the potentiostat are also presented in the paper to validate the stability of the system. The proposed potentiostat was implemented in a standard 0.5 μm CMOS process. The measurement results show that the power consumption of the potentiostat is in the range of 4–10 μW over the physiological glucose concentration range (2–22 mM/L), which produces a sensor current in the range of 0.2–2 μA. These results indicate that the particular topology of the OTA presented in the paper is highly suitable for low power implantable biomedical applications.