Research On High-performance CMOS Transimpedance Amplifiers For Photoelectric Sensors

In recent years,with the rise of the autonomous driving,the consumer market is paying more and more attention to optical laser ranging system.Optical ranging technology typical is comprise of traditional stereo vision and laser active detection.Compared to stereo vision,laser active detection technique has better performance in terms of accuracy and resolution.Due to the development of laser and integrated circuit technology,there is a growing demand for highly integrated Li DAR in the field of autonomous driving,intelligent robotics and consumer electronics.The analog front-end receiver circuit,a significant module of the Li DAR chip,usually enables the detection of the distance information with a single laser shot.The transimpedance amplifier is of the most importance in the analog front-end receiver circuit,and its bandwidth and noise performance have a significant impact on the overall Li DAR system.This thesis focuses on the high performance transimpedance amplifier in the analogue front-end receiver circuit of linear Li DAR.Firstly,the characteristics of Li DAR systems are analysed and the different Li DAR techniques are described,together with the advantages and disadvantages of linear Li DAR systems.Secondly,the performance parameters and key techniques of various transimpedance amplifiers are presented and analysed.Finally,two high performance transimpedance amplifiers are proposed,the layout design is presented,and the post-layout simulation is illustrated.A high bandwidth transimpedance amplifier with differential output is proposed in this thesis.The regulated cascode structure is used here,which can effectively mitigate the influence of the parasitic capacitance of the avalanche photodiode on the stability and bandwidth of the circuit.An active feedback technique is used in the output buffer stage to improve the bandwidth.The proposed transimpedance amplifier is designed in 0.18 ?m CMOS process.The-3-dB bandwidth is approximately 1.122 GHz,the single-ended transimpedance gain is 40 dB? and the symmetry performance of the differential output attain the relatively error of only 1.1 %.This thesis presents an eight-channel transimpedance amplifier.The design uses a multi-path feed-forward compensation technique to effectively reduce the impact of the parasitic capacitance of off-chip avalanche photodiode on loop stability and to improve the bandwidth and phase margin of the circuit.The output stage uses a rail-to-rail operational amplifier to increase the output swing and drive capability of the circuit.The dynamic range is improved with a gain control scheme.The proposed eight-channel transimpedance amplifier is designed in 0.18 ?m CMOS process and the performance is confirmed with the post-layout simulation.The transimpedance gain is 94 dB?,the-3-dB bandwidth of the eight-channel transimpedance amplifier in the high gain band is approximately 251.2 MHz,and the input reference noise current is 2.56 pA/?Hz.