Design of a 50MΩ Transimpedance Amplifier with 0.98fa/√Hz Input Inferred Noise in a 0.18 μM CMOS Technology

摘要

Low noise and low power consumption are key requirements for high performance electrochemical biosensors. Noise performance directly affects the sensor's ability to detect small amounts of target chemical compounds. These requirements present challenges for the design of frontend circuitry in electrochemical biosensors. These challenges are especially apparent for integrated electrochemical biosensor arrays, as sensor size is limited by tissue cell size and the desire to achieve a cellular scale resolution. This paper presents a low-noise and low-power transimpedance amplifier (TIA) intended for (but not limited to) use as an analog frontend in an electrochemical biosensor. The amplifier was designed on a commercial 0.18μm CMOS process. The overall design achieves a 50MΩ transimpedance gain with 981aA/√Hz input inferred noise, 8.06μW power consumption at 0.9V power supply, and occupies an overall silicon area of 0.0074mm~2. To our best knowledge, the design presented in this paper achieved the best noise performance and power consumption among transimpedance amplifier designs reported to date.