A Low-Noise, Low-Offset CMOS Readout IC for Amperometric Biosensors
Electrochemical sensing systems are crucial in driving forward the development of biosensors that is indispensable for health monitoring. In this work, a compact, low-noise, and low-offset CMOS readout circuit has been proposed for amperometric biosensors. It comprises of a transimpedance amplifier,...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IEEE
2024-01-01
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| Series: | IEEE Access |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/10771772/ |
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| Summary: | Electrochemical sensing systems are crucial in driving forward the development of biosensors that is indispensable for health monitoring. In this work, a compact, low-noise, and low-offset CMOS readout circuit has been proposed for amperometric biosensors. It comprises of a transimpedance amplifier, a sample and hold buffer, bias generator, and an on-chip clock generator. A two-step measurement method is introduced to enhance the noise performance and linearity of the signal path. Additionally, a faster and energy-efficient analog autozero scheme is proposed to mitigate amplifier offset and sampled noise, which is a crucial aspect when detecting current in the range of nano-ampere. The proposed readout circuit attains notable specifications, including an input-referred noise of 0.16 pArms, an input-referred offset of 137 nV, an accuracy level of 2%, and a power consumption of 48 <inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>A from a 1.8V supply. It is designed using a 0.18 <inline-formula> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula>m CMOS process and occupies a compact size of 1.47 mm2. This circuit is compatible with a screen-printed electrode sensor and can seamlessly integrate into a flexible printed circuit board. Such integration facilitates its inclusion as a component within a wearable health monitoring system, ensuring expeditious and precise estimation of analyte concentration. |
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| ISSN: | 2169-3536 |