Lidar based solutions SPAD / SiPM art

Laser radar (LiDAR) is a distance measuring technology, in recent years increasingly used in automotive advanced driver assistance systems (ADAS), gesture recognition and 3D mapping applications. Especially in the automotive sector, with the trend of sensor fusion, LiDAR combined with imaging, ultrasound, millimeter-wave radar, complement each other, providing a full range of perception for the automotive, paving the way towards a safer autopilot. Semiconductor sensor solutions provide a full range of this technology and ahead, in the single-photon avalanche diode (the SPAD) and the silicon photomultiplier (the SiPM) sensors is one market leader , provided LiDAR complete solutions, including systems, sensors, and the output of the laser driver scheme. Semiconductor embodiment a complete LiDAR LiDAR system hardware has six major functional blocks: the transmission, reception, beam steering, optical devices, output and power management. Typical LiDAR system block diagram shown in Figure 1. Wherein Semiconductor provides SiPM / SPAD, laser driver reference design, power management, processing and amplification sequence, histogram, and the point cloud generating system. Mature analog SiPM products C series, J series, R series. LiDAR system Demonstrator SiPM array scanning (scanning over 100 m in distance), the fusion of the image sensor SiPM FUSEONE, the latest 400 x 100 SPAD array Pandion.
Figure 1: a block diagram of a typical LiDAR system
What is SPAD, SiPM ToF SPAD and work in a Geiger mode (Geiger Mode) photodiode, the same as the photon trigger switch, in the “open” or “off” state. SiPM SPAD is made up of individual sensors, each sensor has its own quenching resistor , thereby overcoming the lack of a single measurement can not SPAD plurality of photons. Time of flight (the ToF) means sends pulses to the target and the light sensor receives the time required to return from the target. By the speed of light and ToF, calculated from the target, the concept is simple, but by the real-world challenges including harsh environmental conditions such as light, low reflectivity target and long-distance and so on. There are currently twoSpecies ToF measurement techniques: single laser pulse and multi-pulse laser method. A single laser pulse of a single pulse method refers to the time to return each measurement, a high signal to noise ratio requirement (SNR). Multi-pulse method refers to the time a plurality of laser pulses to return each measurement, the data obtained from the histogram, if the improved SNR can be achieved more distant detection. ToF LiDAR can be used in many applications, such as robotics, unmanned aerial vehicles, industrial, mobile, and automotive ADAS autopilot and augmented reality (AR) / virtual reality (VR) and so on. SiPM emerging and are becoming LiDAR SPAD detector SPAD SiPM and detectable distance of more than 200 m, 5% low reflectivity target , can work in bright sunlight, the resolution excellent, and the aperture as small as possible to achieve a compact and solid design system integrated into the car, and cost-competitive, is becoming a new LiDAR sensor. 1. car LiDAR sensors require strict consistency due SiPM / SPAD operate in Geiger mode, it is difficult to control product consistency. ON Semiconductor is the world’s truly capable of high-volume production supplier SiPM products, voltage and gain millions of sensors which provide a very consistent, easy-to-system calibration and reduce manufacturing costs. 2. Meet the car rules (IATF 16949, AEC Q102, -40 to 1050C operating temperature, in line with PPAP) ON Semiconductor has accumulated years of professional experience in automobile production, have an excellent car rules product quality supervision and control system [ 123] control Engineering Copyright , designed from the outset to consider the car certified to design sensors and packaging. 3. In the 905 nm at high photon detection rate (PDE) ON Semiconductor SiPM now have best-in-PDE, more than 12% in 2020 to reach 30%. 4. SiPM gain high gain avalanche photodiode (APD) 000 times, 100 times a PIN diode, crosstalk Copyright Control Engineering <20,提供出色的SNR。  SiPM 阵列扫描LiDAR 系统  该SiPM 阵列扫描LiDAR含16个905 nm 激光二极管、1个用于光束转向的机电旋转镜、安森美半导体的单片1 x 16 SiPM 阵列和处理电子器件,视场角(AoV) 80°x 5.53°,脉宽1 ns,系统峰值功率400 W,系统尺寸22 cm x 18 cm x 13 cm。这系统采用1D阵列同时采样多个垂直点,并结合水平单轴扫描, the complete image field of view can be obtained, to achieve a long low reflectivity from real-time imaging target. FUSEONE system: fused image and LiDAR FUSEONE combined 2-megapixel auto-level imageSiPM based sensors and flash LiDAR, LiDAR fusion camera and software application, access to the target distance, a moving speed data, and high sensitivity detectors SiPM phantom intelligent algorithm to enhance the ability of distance. Since no mechanical scanning radar type, FUSEONE cost-competitive. The system uses two and eight SiPM diode laser 905 nm, pulse width of 20 ns, the peak power of 80 W, the receiver uses the optical path 43 nm bandpass filter, Xilinx FPGA full-edge treatment for waveform acquisition, at 25 ° AoV x 3.6 °, under outdoor lighting conditions of 20 klux, pedestrian detection of 45 m, the detection of car 85 m. Pandion SPAD array to achieve a long distance 400 × 100 SPAD array scanning LiDAR having a CMOS logic device, array size 14 mm × 3 mm, the pixel pitch of 38.6 um, using the rolling shutter read-out (100 channel parallel readout), passive quenched with active reset (PQAR) characteristic can be obtained FIG. 2: Pandion probe target different reflectivity different from <5 ns恢复时间,击穿电压达3.3 V以上。区别于传统的点云,Pandion SPAD LiDAR已形成了图像。
FIG. 3: Pandion intensity image using photon counts obtained
FIG. 4: dim light intensity of the image at a level Pandion
summarizes SiPM and SPAD technology is key to achieving LiDAR system receiver functions based on Geiger mode avalanche principle, compact, high-gain sensor, oN semiconductor is the market leader in these technologies, to provide a complete LiDAR program, including SiPM sensor, SiPM array scanning LiDAR systems integration FUSEONE system SiPM flash LiDAR and image as well as Pandion SPAD array, with strong, cost-effective, consistent car rules and other advantages, and actively research and innovation, while providing a wide range of field application designers support related application notes, and video library, product presentation systems, the Verify the simulation data model and so on, to solve design challenges and promote innovation.

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