An Automotive LiDAR SoC for 240 × 192-Pixel 225-m-Range Imaging with a 40-Channel 0.0036-mm2Voltage/Time Dual-Data-Converter-Based AFE

Satoshi Kondo, Hiroshi Kubota, Hisaaki Katagiri, Yutaka Ota, Masatoshi Hirono, Tuan Thanh Ta, Hidenori Okuni, Shinichi Ohtsuka, Yoshinari Ojima, Tomohiko Sugimoto, Hirotomo Ishii, Kentaro Yoshioka, Katsuyuki Kimura, Akihide Sai, Nobu Matsumoto

Research output: Contribution to journalArticlepeer-review

Abstract

This article presents a 40-channel high-resolution automotive LiDAR system-on-chip (SoC), which utilizes the world's first dual-data converter (DDC). The proposed DDC consolidates the functions of ADC and TDC into a single circuitry and achieves acquisition of both high-precision time and voltage data from the input, realizing a 5 times smaller analog front-end (AFE) area than prior arts. Such innovations lead us to a 40-channel AFE integration of the SoC without silicon cost increase, which characterizes our LiDAR system with 2 times higher pixel resolution. To enhance the ADC's signal-to-noise and distortion ratio (SNDR) without sacrificing the area efficiency, a calibration-free and variation-tolerant voltage-controlled oscillator (VCO)-based ADC with a multiphase pulse density modulator (MP-PDM)-based feedback is proposed. Our proof-of-concept LiDAR system achieves a measurement range of 225 m at 70-klx direct sunlight, with a resolution of 240 times 192 pixels at 10 frames per second (FPS). To quantitatively measure the effect of the resolution improvement of our LiDAR, we evaluate the LiDAR's detection accuracy of small targets 75 m away. Due to the 2 times higher vertical pixel resolution, our LiDAR can detect targets with 2 times smaller height. The 3-D point cloud of the LiDAR captured outdoor in the wild is presented.

Original languageEnglish
Article number9197615
Pages (from-to)2866-2877
Number of pages12
JournalIEEE Journal of Solid-State Circuits
Volume55
Issue number11
DOIs
Publication statusPublished - 2020 Nov
Externally publishedYes

Keywords

  • ADC
  • dual-data converter (DDC)
  • LiDAR
  • range measurement
  • TDC
  • time of flight (ToF)
  • voltage-controlled oscillator (VCO)-based ADC

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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