Abstract: An example apparatus, computer-implemented method, and electronic device comprising an ambient light sensor configured to mitigate the effects of dark count rate associated with avalanche photodiodes are provided. The example apparatus includes an exposed avalanche photodiode array, a dark avalanche photodiode array, and a controller. The exposed avalanche photodiode array is positioned to receive ambient light from an external environment. The dark avalanche photodiode array is obscured from the ambient light. The controller is configured to receive an exposed illumination count corresponding to the ambient light received at the exposed avalanche photodiode array. The controller is further configured to receive a dark illumination count corresponding to a dark count at the dark avalanche photodiode array. The controller determines an ambient light value based on a difference between the exposed illumination count and the dark illumination count.

Abstract: An example macropixel, an image sensor comprising a plurality of macropixels, a high resolution scanner based on an array of macropixels, and a time delay integration sensor utilizing an array macropixels are provided. The example macropixel includes photodiodes, memory devices, and switching circuitry configured to switch between a high dynamic range image capture mode and a time-of-flight sensing mode. The memory devices, include at least one memory device for each photodiode in the plurality of photodiodes. During the high dynamic range image capture mode, a corresponding memory device is configured to determine an individual intensity of light received at a particular photodiode. During the time-of-flight sensing mode, each memory device is configured to determine an intensity of light received at a group of photodiodes during a time period, wherein each memory device is associated with a different time period.

Abstract: According to an embodiment, a method to mitigate target wraparound in time-of-flight is proposed. The method includes extending the system's pulse interval to include predetermined and dynamic blanking times. The dynamic blanking time is increased by an offset at each successive pulse. The dynamic blanking time is reset in response to reaching a predetermined dynamic blanking time. The dynamic blanking time is initially set to zero. The method further includes processing events within an active window to measure a time interval between the transmission of a pulse and the receipt of a reflected pulse from an object. The duration of the active window is equal to the duration of the initial pulse interval. The method further includes ignoring events within an inactive window, a duration of the inactive window corresponding to the duration of the extended pulse interval minus the duration of the active window.

Abstract: A time-of-flight system includes an emitter-circuit generating and directing pulses of light toward a target, and a receiver-circuit including a photodetector coupled between a bias node and a sensing node to detect pulses that have reflected off the target, a comparison circuit comparing a sense voltage at the sensing node to a reference, a timing measurement circuit measuring elapsed time between generation of a given pulse and detection thereof after reflection off the target, and a programmable current sink that sinks a current from the sensing node equal to a portion of a photocurrent generated by the photodetector due to detection of ambient light. A timing-generation circuit synchronizes generation of the pulses and measurement of elapsed time by the timing circuit. A processor adjusts a magnitude of the current sunk from the sensing node based upon output of the comparison circuit when the emitter circuit is deactivated.

Abstract: A time-of-flight (TOF) system includes a driver driving a VCSEL-array to emit light, a reference array receiving a reference light-signal, and a return array receiving emitted light that reflects off a target. Reference readout circuitry reads out the reference array. Return readout circuitry reads out the return array. A first buffer-driver buffers a base timing-reference to produce a first timing-reference. A second buffer-driver buffers the first timing-reference to produce a second timing-reference. Calibration circuitry takes a first TOF-measurement using the return readout circuitry when it is clocked by the first timing-reference, takes a second time of flight measurement using the return readout circuitry when it is clocked by the second timing-reference, and compensates for an offset between TOF taken by the return readout circuitry and the reference readout circuitry during normal operation based on the first and second TOF-measurements.

Abstract: In an embodiment, a method includes: receiving a first plurality of digital codes from a time-to-digital converter (TDC); generating a coarse histogram from the first plurality of digital codes; detecting a peak coarse bin from the plurality of coarse bins; after receiving the first plurality of digital codes, receiving a second plurality of digital codes from the TDC; and generating a fine histogram from the second plurality of digital codes based on the detected peak coarse bin, where a fine histogram depth range is narrower than a coarse histogram depth range, where a lowest fine histogram depth is lower or equal to a lowest coarse peak depth, and where a highest fine histogram depth is higher or equal to a highest coarse peak depth.

Abstract: An imaging device includes a sensor array with a number of pixels. In an embodiment, the imaging device can be operated by capturing a first low-spatial resolution frame using a subset of pixels of the sensor array and then capturing a second low-spatial resolution frame using the same subset of pixels of the sensor array. A first depth map is generated using raw pixel values of the first low-spatial resolution frame and a second depth map is generated using raw pixel values of the second low-spatial resolution frame. The first depth map can be compared to the second depth map to determine whether an object has moved in a field of view of the imaging device.

Abstract: A single photon avalanche diode (SPAD) pixel circuit includes a SPAD, a clamping transistor coupled to the anode of the SPAD, and readout circuitry. The clamping transistor limits the anode voltage to a threshold below the readout circuitry's maximum operating voltage. In one embodiment, quenching and enabling transistors are implemented using single-layer gate oxide technology, while the clamping transistor uses extended drain technology. A regulation circuit generates a voltage clamp control signal for an array of pixels. Another embodiment utilizes a stacked chip design with the SPAD and a cathode-side quenching element on one chip, and the clamping transistor and readout circuitry on another. This incorporates a parasitic capacitance from deep trench isolation. Additional biasing transistors may be used for fine-tuning the clamped anode voltage.

Abstract: Disclosed herein is an array of pixels. Each pixel includes a single photon avalanche diode (SPAD) and a transistor circuit. The transistor circuit includes a clamp transistor configured to clamp an anode voltage of the SPAD to be no more than a threshold clamped anode voltage, and a quenching element in series with the clamp transistor and configured to quench the anode voltage of the SPAD when the SPAD is struck by an incoming photon. Readout circuitry is coupled to receive the clamped anode voltage from the transistor circuit and to generate a pixel output therefrom, the threshold clamped anode voltage being below a maximum voltage rating of transistors forming the readout circuitry.

Abstract: A system-on-a-chip (SOC) within a package includes a reference generator, a matching circuit, a programmable current generator, a PWM controller, an overvoltage/undervoltage detector receiving a high voltage from a third output pad, a multiplexer passing an input signal to a second output pad, and a SPAD receiving the high voltage. Switching circuitry includes a first switch between the reference generator and an input of the programmable current generator, a second switch between the input of the current generator and the output of the matching circuit, a third switch between the reference generator and an input of the matching circuit, a fourth switch between an output of the current generator and a tap of a ladder within the overvoltage/undervoltage detector, a fifth switch between an output of the current generator and the first output pad, and a sixth switch between the output of the PWM controller and the first output pad.

Abstract: In an embodiment, an optoelectronic device includes a light source and an array of pixels. Each pixel of the array is configured to detect an amount of return light falling in each of a subset of time intervals that form a detection time window of the pixel. A time window position code generator is configured to generate a sequence of time window position codes. Each pixel includes a memory configured to store a first reference time window position associated with the pixel, a time window code comparator configured to compare a first time window position code of the sequence with the first reference time window position, and a timing sequence generator configured to generate, when the comparison indicates a match, a time window control signal configured to activate the detection of the return light during a detection time window selected by the time window control signal.

Abstract: A laser diode driver circuit includes a first pair of contacts and connectors coupled to an anode of the laser diode. An inductance of each of the first pair of contacts and connectors is the same. A second pair of contacts and connectors are coupled to a cathode of the laser diode. An inductance of each of the second pair of contacts and connectors is the same. The laser diode driver circuit also includes current driving circuitry.

Abstract: In an embodiment, a method includes: resetting respective count values of a plurality of analog counters to an initial count value, each analog counter of the plurality of analog counters corresponding to a histogram bin of a time-of-flight (ToF) histogram; after resetting the respective count values, receiving a plurality of digital addresses from a time-to-digital converter (TDC); during an integration period, for each received digital address, selecting one analog counter based on the received digital address, and changing the respective count value of the selected one analog counter towards a second count value by a discrete amount, where each analog counter has a final count value at an end of the integration period; and after the integration period, determining an associated final bin count of each histogram bin of the ToF histogram based on the final count value of the corresponding analog counter.

Abstract: In some embodiments, a ToF sensor includes an illumination source module, a transmitter lens module, a receiver lens module, and an integrated circuit that includes a ToF imaging array. The ToF imaging array includes a plurality of SPADs and a plurality of ToF channels coupled to the plurality of SPADs. In a first mode, the ToF imaging array is configured to select a first group of SPADs corresponding to a first FoV. In a second mode, the ToF imaging array is configured to select a second group of SPADs corresponding to a second FoV different than the first FoV.

Abstract: In an embodiment, a method includes: receiving a first plurality of digital codes from a TDC; generating a coarse histogram from the first plurality of digital codes; detecting a peak coarse bin from the plurality of coarse bins; after receiving the first plurality of digital codes, receiving a second plurality of digital codes from the TDC; and generating a fine histogram from the second plurality of digital codes based on the detected peak coarse bin, where a fine histogram depth range is narrower than a coarse histogram depth range, where a lower fine histogram depth is lower or equal to a lower coarse peak depth, and where a higher fine histogram depth is higher or equal to a higher coarse peak depth.

Abstract: A system-on-a-chip (SOC) within a package includes a reference generator, a matching circuit, a programmable current generator, a PWM controller, an overvoltage/undervoltage detector receiving a high voltage from a third output pad, a multiplexer passing an input signal to a second output pad, and a SPAD receiving the high voltage. Switching circuitry includes a first switch between the reference generator and an input of the programmable current generator, a second switch between the input of the current generator and the output of the matching circuit, a third switch between the reference generator and an input of the matching circuit, a fourth switch between an output of the current generator and a tap of a ladder within the overvoltage/undervoltage detector, a fifth switch between an output of the current generator and the first output pad, and a sixth switch between the output of the PWM controller and the first output pad.

Abstract: An optical sensor includes at least one photodetector configured to be reverse biased at a voltage exceeding a breakdown voltage by an excess bias voltage. At least one control unit is configured to adjust the reverse bias of the at least one photodetector. A method of operating an optical sensor is also disclosed.

Abstract: A depth map sensor includes a first array of first pixels, each first pixel having a first photodetector associated with a pixel circuit that comprises a plurality of first bins for accumulating events. A clock source is configured to generate a plurality of phase-shifted clock signals. A first circuit has a plurality of first output lines coupled to the first array of first pixels. The first circuit is configured to receive the plurality of phase-shifted clock signals. The first circuit includes a first block and a second block. The first block is configured to propagate the plurality of phase-shifted clock signals to the second block during a first period determined by a first enable signal and the second block configured to select to which of the plurality of first output lines each of the plurality of phase-shifted clock signals is applied.

Abstract: An example method, to determine time of flight for light detection and ranging, includes enabling a time to digital converter; emitting a light pulse after enabling the time to digital converter; initiating a sampling window at a time of emission of the light pulse; using the time to digital converter to determine times of flight for photons detected during the sampling window; initiating a blanking period in response to concluding the sampling window; and disabling the time to digital converter in response to initiation of the blanking period.

Abstract: In an embodiment, a method includes: receiving a first plurality of digital codes from a time-to-digital converter (TDC); TDC; generating a coarse histogram from the first plurality of digital codes; detecting a peak coarse bin from the plurality of coarse bins; after receiving the first plurality of digital codes, receiving a second plurality of digital codes from the TDC; and generating a fine histogram from the second plurality of digital codes based on the detected peak coarse bin, where a fine histogram depth range is narrower than a coarse histogram depth range, where a lowest fine histogram depth is lower or equal to a lowest coarse peak depth, and where a highest fine histogram depth is higher or equal to a highest coarse peak depth.