Design of a Transimpedance Amplifier with T-Network and DC Signal Rejection Structure for Photoelectric Sensors

Measurement systems using current-output sensors typically include transimpedance amplifiers (TIAs). This article studies a TIA with T-network and DC signal rejection structure for low-cost photoelectric sensors, where the TIA structure, frequency response, and bandwidth characteristics were analyzed. Using TIAs composed of different amplifiers with T-network and DC signal rejection structure, the relevant frequency response and bandwidth characteristics were obtained. Through comparing the TIA responses with the dynamic output of a photodiode sensor or the current source of 5 constant output as inputs, experiments were conducted to verify the dynamic performance of the optimal TIA with T-network. Accordingly, to evaluate the impact of TIA nonlinearity on the its performance by switching on or off the current source. Compared with traditional TIA, the experimental results show that the proposed TIA circuit has a high bandwidth, low noise, high signal-to-noise ratio, good dynamic performance and can meet the needs of optoelectronic conversion. The proposed circuit structure can also be applied to various other applications, such as optical communication systems and biosensors.