A Rail-to-Rail Operational Amplifier for Transimpedance Optoelectronic Conversion

Abstract

The transimpedance conversion circuit is an important part of the fluorescent optical fiber temperature sensor, which is used for rare earth fluorescence detection. Transimpedance conversion circuits can benefit from the wide input range, high gain, low input offset voltage, and high common-mode rejection ratio of rail-to-rail operational amplifiers. In this paper, a constant transconductance rail-to-rail operational amplifier is designed and implemented based on the 0.18 μm CMOS process. According to the simulation results, the transconductance change rate of the operational amplifier is 4.8%, and its gain is 140 dB. The input offset voltage of this operational amplifier is 0.41 μV. Both the power supply rejection ratio and the common-mode rejection ratio have values above 140 dB, with the common-mode rejection ratio reaching as high as 165.4 dB. The transimpedance conversion circuit consists of the operational amplifier designed in this paper. The test results show that the operational amplifier has a certain application value in the transimpedance amplification circuit.