READOUT VOLTAGE UNCERTAINTY COMPENSATION IN TIME-OF-FLIGHT IMAGING PIXELS

• Main Authors: Nagaraja, Satyadev H, Akkaya, Onur Can, Rajasekaran, Vijay, Elkhatib, Tamer, Bamji, Cyrus Soli, Mehta, Swati
• Format: Patent
• Language: English
• Published: 31.10.2019
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION; RADIO DIRECTION-FINDING; RADIO NAVIGATION; TESTING

Pixel arrangements in time-of-flight sensors are presented that include sensing elements that establish charges related to incident light, charge storage elements that accumulate integrated charges transferred from the sensing elements, and diffusion nodes configured to establish measurement voltages representative of the integrated charges that are dumped from the charge storage elements. The pixel arrangement includes analog domain output circuitry comprising a measurement capacitance element that stores the measurement voltage, and a reset capacitance element that stores a reset voltage established at the diffusion node during a reset phase performed prior to a measurement phase. The analog domain output circuitry subtracts the stored reset voltage from the stored measurement voltage for processing into a pixel output voltage that at least partially reduces readout voltage uncertainty of the pixel arrangement.