Roh, Wonjong Seo, Hyeongseok Piao, Canxing Kim, Minkyung Jeon, Taehoon Lee, Heesung Lee, Myung-Jae Chun, Jung-Hoon Kim, Seong-Jin Choi, Jaehyuk 2025-06-24T02:30:34Z 2025-06-24T02:30:34Z 2025-06-23 2025-10 0018-9200 https://pubs.kist.re.kr/handle/201004/152682 An area-efficient, high-resolution CMOS light detection and ranging (LiDAR) capable of generating $400 \times 112$ depth images is proposed. This sensor employs a rolling-scan architecture that is compatible with a row-addressable solid-state LiDAR system. To achieve high resolution, a single-photon avalanche diode (SPAD) analog front-end (AFE) circuit was implemented using only five nMOS transistors. A reconfigurable-resolution (RR) hTDC, capable of converting one-/two-channel signals with variable time resolutions of 1, 2, or 4 ns, is further proposed to implement a 400-channel histogramming time-to-digital converter (hTDC) with low memory overhead. The sensor leverages RR-hTDC to support two image resolution modes: macro and quadruple resolution (QR). In the macro mode, $200 \times 56$ depth images can be acquired with a 1-ns time resolution. In the QR mode, the sensor can achieve $400 \times 112$ high-resolution depth images with a 2-ns time resolution. In the range-enhanced (RE) mode, the time resolution is halved for distances beyond 100 m, enabling the detection range to be extended up to 200m. A laser profile-based depth refining (DR) filter was used to compensate for the reduction in time resolution and ensure sub-centimeter time resolution, improving depth precision by 40% compared with the conventional QR mode. The prototype LiDAR sensor was fabricated as a 90-nm CMOS image sensor (CIS) process. In outdoor conditions under 135-klx sunlight, the worst case depth precision and accuracy for distances of 15-60 m were measured as 10 and 17 cm, respectively. Moreover, a relative precision of less than 0.18% was achieved over a 60-130-m range under 90-klx sunlight. The total power consumption of the sensor was measured to be 572 mW when operating at 20 frames/s under 70-klx sunlight. English Institute of Electrical and Electronics Engineers A High-Resolution Solid-State LiDAR Sensor With Reconfigurable Histogramming Time-to-Digital Converter and Filter for Depth Refinement Article 10.1109/JSSC.2025.3571446 1 IEEE Journal of Solid-State Circuits, v.60, no.10, pp.3665 - 3681 IEEE Journal of Solid-State Circuits 60 10 3665 3681 N scie scopus 001504195400001 2-s2.0-105007614140 Engineering, Electrical & Electronic Engineering Article FLASH LIDAR RANGE SOC histogramming time-to-digital converter (hTDC) light detection and ranging (LiDAR) reconfigurable-resolution hTDC (RR-hTDC) single-photon avalanche diode (SPAD) SPAD analog front end (AFE) Image resolution Laser radar Single-photon avalanche diodes Vertical cavity surface emitting lasers Photonics Spatial resolution Signal resolution Optical filters Histograms Robot sensing systems CMOS depth sensor depth refining filter (DRF) direct time of flight (dToF) high-resolution LiDAR