Low power time-of-flight 3D imager system in standard CMOS

Abstract

This paper proposes a novel time-of-flight (ToF) sensor with high dynamic range and fine depth resolution for medium and long range 3D imaging applications. It focuses on low power consumption while maintaining human-eye safety requirements. A pixel array architecture is employed where each pixel consists of a single-photon avalanche diode (SPAD) as a photo-detector along with a dedicated time-to-digital converter (TDC) for fast image acquisition. The imager is designed to achieve millimeter-level depth resolution with maximum range up to 30 m operating at a maximum frame rate of 1000 fps. It targets security applications, primarily facial recognition, but is also suitable for automotive vision and robotics.