A low power 100MΩ CMOS front-end transimpedance amplifier for biosensing applications

In this paper, the design, implementation and simulation of a high-gain, low-power, low-noise CMOS front-end transimpedance amplifier (TIA) is presented for interfacing with a bio-sensor array and analog neural circuits. An improved capacitive-feedback TIA topology is used with an active load to obtain a 100MΩ transimpedance gain, 1MHz bandwidth, 158fA/rt(Hz) input-referred current noise at sensing frequency, near 0° phase shift and 1V peak-to-peak output swing. The proposed circuit dissipates 132μW from a 1.8V supply and the circuit is implemented in a standard 0.18μm CMOS 1P6M technology.