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

This paper presents a 128 × 128 SPAD flash LiDAR sensor incorporating an array of 32 × 32 320µm²-TDCs; thanks to the compact TDC, more pixel area becomes available for the registers needed to store TDC output data temporarily for off-chip histogramming. The sensor was fabricated in a 130 nm SiGe technology and achieves a measurement range of 57 m with a distance precision of 6.4 cm (sigma) at that range under a 300lx background, whereas with a maximum frame rate of 13fps at a 126klx background illumination. Benefiting from the performance of the SiGe technology, the integrated TDC achieves a resolution of 125ps. The sensor consumes a total power of 180 mW under an indoor environment, of which 121.4 mW is dissipated by the 16-channel LVDS data interface and 58.7 mW by the 128 × 128 pixel array.