Design Of High Performance Narrow Pulse Semiconductor Laser Driver Circuit For LiDAR

LiDAR has the advantages of long distance,good directivity and high efficiency,and is widely used in unmanned driving,intelligent robot,topographic surveying and mapping and other fields.The detection performance of LiDAR is closely related to the quality of the optical pulse emitted by the laser source,and the quality of the optical pulse is directly determined by the semiconductor laser driving circuit.In order to realize the long-distance and high precision detection,the high power and narrow pulse width laser driving technology has become the focus of research at present.The traditional semiconductor laser drive circuit is mainly composed of high voltage power supply module,which has the problems of large volume,poor reliability and high cost.In order to improve the detection performance of LiDAR,the research of semiconductor laser driving circuit is of great significance.In this paper,a semiconductor laser driver circuit is designed based on high-speed switches,inductors,capacitors and other components,and the stability of the driver circuit is improved by thermal simulation optimization method.Finally,the circuit has the characteristics of high power,narrow pulse width and miniaturization.Firstly,the overall structure of the driving circuit is determined by the technical index,including the high-speed switching circuit,the booster circuit and the capacitive discharge driving unit.The high-speed switching circuit is designed with MOSFET and driver chip,which improves the switching speed and realizes the nanosecond level switching.Based on the principle of inductive energy storage,the voltage booster circuit and its working mode are designed to achieve the function of providing transient high voltage for the circuit and avoid the introduction of high voltage module.The working state of the capacitive discharge driving unit is determined by establishing the actual circuit model,and the transient parameter scanning simulation of the circuit is carried out by using ORCAD PSPICE software.The circuit parameter design is completed,and the current pulse of high current and narrow pulse width is realized.On this basis,in view of the semiconductor laser output power of the decline of the working temperature of the circuit,was carried out by using ANSYS Icepak software heat temperature field of semiconductor laser driver circuit optimization design,to realize the drive circuit of low working temperature,heat transfer more uniform design,in order to improve the stability of the circuit.Finally,the drive circuit board is 23 mm×9 mm,and it is tested.The test results show that the circuit operates on the low voltage DC power supply,and the high voltage of 100 V is realized by the booster circuit.The output laser pulse width is 3.8ns,the peak power is more than 300 W,and the highest repetition frequency is 40 k Hz.In the absence of an external temperature control system,the semiconductor laser drive circuit can operate stably at a higher ambient temperature of 45 ℃ when the repetition frequency of the current vehicular LiDAR is 20 kHz.