NON-SPAD PIXELS FOR DIRECT TIME-OF-FLIGHT RANGE MEASUREMENT

摘要

A Direct Time-of-Flight (DTOF) technique is combined with analog amplitude modulation within each pixel in a pixel array. No Single Photon Avalanche Diodes (SPADs) or Avalanche Photo Diodes (APDs) are used. Instead, each pixel has a Photo Diode (PD) with a conversion gain of over 400 μV/e− and Photon Detection Efficiency (PDE) of more than 45%, operating in conjunction with a Pinned Photo Diode (PPD). The TOF information is added to the received light signal by the analog domain-based single-ended to differential converter inside the pixel itself. The output of the PD in a pixel is used to control the operation of the PPD. The charge transfer from the PPD is stopped—and, hence, TOF value and range of an object are recorded—when the output from the PD in the pixel is triggered within a pre-defined time interval. Such pixels provide for an improved autonomous navigation system for drivers.