Review and Analysis of CMOS Current Readout Circuits for Biosensing Applications

CMOS current readout is a critical circuit block for various applications like bio-sensing. This paper presents an overview of CMOS current readout techniques and analyze their merits and demerits, including noise floor, sensitivity, and achievable system bandwidth. Mainly, the practical applicability of individual technique/design for integrated low-noise bio-sensing applications is discussed. To present a thorough insight of the state-of-the-art, most recent and relevant articles published in the literature related to the current sensing interface are summarized and compared. The paper identified the primary DC current rejection schemes, where each approach and its limitations are discussed and shown that each system comes with its limits.