128 × 128 SPAD flash LiDAR in 130 nm SiGe technology with a shared distributed-clock TDC array

Area of Science:

• Photonics and Sensing Technologies
• Integrated Circuits and Systems
• LiDAR and 3D Imaging

Background:

• Traditional LiDAR systems face limitations in resolution and power consumption.
• The need for compact, high-performance LiDAR sensors is growing for applications like autonomous driving and robotics.
• Advancements in Silicon-Germanium (SiGe) technology offer potential for improved sensor performance.

Purpose of the Study:

• To present a novel 128x128 SPAD flash LiDAR sensor with integrated Time-to-Digital Converters (TDCs).
• To demonstrate the sensor's performance in terms of range, precision, and frame rate.
• To evaluate the sensor's power consumption and the benefits of SiGe technology.

Main Methods:

• Fabrication of a 128x128 SPAD flash LiDAR sensor using 130nm SiGe technology.
• Integration of 32x32 TDCs with a size of 320µm² per pixel.
• Testing the sensor's performance under varying background illumination conditions (300lx and 126klx).

Main Results:

• Achieved a measurement range of 57m with a distance precision of 6.4cm (sigma) at 300lx background.
• Maximum frame rate of 13fps achieved at a 126klx background illumination.
• Integrated TDC resolution of 125ps and total power consumption of 180mW.

Conclusions:

• The developed SPAD flash LiDAR sensor offers a compelling combination of range, precision, and frame rate.
• The compact TDC design allows for increased pixel area, enhancing data handling capabilities.
• SiGe technology proves effective for fabricating high-performance LiDAR sensors with moderate power consumption.