A 0.18- m CMOS SoC for a 100-m-Range 10-Frame/s 200 96-Pixel Time-of-Flight

Abstract

With the emerging need for high-resolution light detection and ranging (LIDAR) te chnologies in advanced driver assistance systems (ADAS), we introduce a system-on-a-chip (SoC) that performs time-correlated single-photon counting an d complete digital signal processing for a time-of- flight (TOF) sensor. At the core of the 0.18- m CMOS SoC, we utilize linear arrays of 16 TOF and 32 intensity-only macro-pixels based on single-photon avalanche diodes in an original look-ahead concept, thus acquiring active TOF and passive intensity images simul- taneously. The SoC also comprises an array of circuits capable of generating precise triggers upo n spatiotemporal correlation events, an array of 64 12-b time-to-digital converters, and 768 kb of SRAM memory. The SoC provides the system-level el ectronics with a serial and low-bit-rate digit al interface for: 1) multi-echo distance; 2) distance reliability; 3) intensity; and 4) passive-only intensity, thus mitigating system-level co mplexity and cost. A proof-of-concept prototype that achieves depth imaging up to 100 m with a resolution of 202 96 pixels at 10 frames/s has been implemented. Quantitative evaluation of the TOF sensor under strong solar background illuminance, i.e., 70 klux, revealed a repeatability error of 14.2 cm throughout the distance range of 100 m, thus leading to a relative precisi on of 0.14%. Under the same conditions, the relative nonlinearity error was 0.11%. In order to show the suitability of our approach for