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 single photon avalanche diode based range detecting apparatus includes a reference array of single photon avalanche diodes configured to receive light from an illumination source via an internally coupled path. A return array of single photon avalanche diodes is configured to receive light from the illumination source via an external free space path. A calibration pulse generator is configured to generate a calibration signal pulse. Readout circuitry is configured to receive an output of the reference array via a reference signal path, an output of the return array via a return signal path, and an output of the calibration pulse generator via a calibration signal path. The readout circuitry is configured to determine a delay difference value between the reference signal path and the return signal path based on the output of the calibration pulse generator via the calibration signal path.

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: An indirect time of flight sensor includes a matrix of pixels, wherein each pixel includes at least two controllable transfer devices. First conductive lines transmit first control signals to the transfer devices, these first signals being provided by a first circuit. A device is provided for illuminating a scene that is divided into at least two first areas. The device successively illuminates each first area. The matrix is similarly divided into at least two second areas. The matrix and illumination device are disposed such that each first area corresponds to one second area. The first circuit provides different first signals to the different second areas.

Abstract: In an embodiment, a method includes: providing a gray-coded time reference to a time-to-digital converter (TDC); receiving an event from an event signal; latching the gray-coded time reference into a memory upon reception of the event signal; and updating a time-of-flight (ToF) histogram based on the latched gray-coded time reference.

Abstract: A pixel includes a single photon avalanche diode (SPAD) having a cathode coupled to a high voltage supply through a quenching element, with the SPAD having a capacitance at its anode formed from a deep trench isolation, with the quenching element having a sufficiently high resistance such that the capacitance is not fully charged when the SPAD is struck by an incoming photon. The pixel includes a clamp transistor configured to be controlled by a voltage clamp control signal to clamp voltage at an anode of the SPAD when the SPAD is struck by an incoming photon to be no more than a threshold clamped anode voltage, and readout circuitry coupled to receive the clamped anode voltage from the clamp transistor and to generate a pixel output therefrom. The threshold clamped anode voltage is below a maximum operating voltage rating of transistors forming the readout circuitry.

Abstract: In an embodiment of the present invention, a method for controlling a voltage across a single photon avalanche diode includes: providing an output based on a current flowing through the single photon avalanche diode; and controlling the voltage applied across the single photon avalanche diode based on the provided output.

Abstract: The present disclosure is directed to a diode including a first doped structure, doped with a first type of material and forming at least part of an isolation structure for the diode; at least one contact structure located within the first doped structure, the at least one contact structure forming one of the cathode or anode of the diode; a second doped structure, doped with a second type of material, and forming at least one depletion region or PN junction with the first doped structure; at least one second contact structure located within the second doped structure, the at least one second contact structure forming the other of the anode or the cathode of the diode; at least one further contact structure, doped with the first type of material, the at least one further contact structure forming at least one further depletion region or further PN junction, such that the at least one further depletion region is configured to steer charge from the at least one depletion region and thus decrease the sensitivity

Abstract: A ToF sensor includes an array of pixels having first and second subsets of pixels, first and second pluralities of TDCs, a routing bus having first and second pluralities of bus drivers, and a controller configured to: when the first subset of pixels is active and the second subset of pixels is not active, control the first plurality of bus drivers to route events from half of the pixels of the first subset to the first plurality of TDCs and control the first and second pluralities of bus drivers to route events from the other half of the pixels of the first subset to the second plurality of TDCs, and when the first subset of pixels is not active and the second subset of pixels is active, control the first plurality of bus drivers to route events from the second subset of pixels to the first plurality of TDCs.

Abstract: A method includes receiving a histogram output from a detector sensor, and calculating a median point of a pulse waveform within the histogram. The pulse waveform has an even probability distribution over at least one quantization step of the histogram around the median point. A corresponding apparatus can include a detector sensor and a co-processor coupled to the detector sensor.

Abstract: An apparatus can be used for detecting pile-up within circuitry associated with photodetectors. The apparatus includes an input terminal configured to receive a plurality of photodetector outputs. An OR-tree is coupled in parallel with the circuitry associated with the photodetectors. The OR-tree has an input coupled to the input terminal and is configured to combine the photodetector outputs. A counter is configured to count an output of the OR-tree. A comparator is configured to compare an output of the counter to a determined threshold value, wherein the comparator is configured to output an indicator indicating pile-up within the circuitry associated with photodetectors based on the output of the counter being greater than or equal to the determined threshold value.

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: In an embodiment, a method includes: providing a gray-coded time reference to a time-to-digital converter (TDC); receiving an event from an event signal; latching the gray-coded time reference into a memory upon reception of the event signal; and updating a time-of-flight (ToF) histogram based on the latched gray-coded time reference.

Abstract: A method includes receiving a histogram output from a detector sensor, and calculating a median point of a pulse waveform within the histogram. The pulse waveform has an even probability distribution over at least one quantization step of the histogram around the median point. A corresponding apparatus can include a detector sensor and a co-processor coupled to the detector sensor.

Abstract: A pixel includes a single photon avalanche diode (SPAD) having a cathode coupled to a high voltage supply through a quenching element, with the SPAD having a capacitance at its anode formed from a deep trench isolation, with the quenching element having a sufficiently high resistance such that the capacitance is not fully charged when the SPAD is struck by an incoming photon. The pixel includes a clamp transistor configured to be controlled by a voltage clamp control signal to clamp voltage at an anode of the SPAD when the SPAD is struck by an incoming photon to be no more than a threshold clamped anode voltage, and readout circuitry coupled to receive the clamped anode voltage from the clamp transistor and to generate a pixel output therefrom. The threshold clamped anode voltage is below a maximum operating voltage rating of transistors forming the readout circuitry.

Abstract: A single photon avalanche diode based range detecting apparatus includes a reference array of single photon avalanche diodes configured to receive light from an illumination source via an internally coupled path. A return array of single photon avalanche diodes is configured to receive light from the illumination source via an external free space path. A calibration pulse generator is configured to generate a calibration signal pulse. Readout circuitry is configured to receive an output of the reference array via a reference signal path, an output of the return array via a return signal path, and an output of the calibration pulse generator via a calibration signal path. The readout circuitry is configured to determine a delay difference value between the reference signal path and the return signal path based on the output of the calibration pulse generator via the calibration signal path.

Abstract: A time-of-flight ranging system disclosed herein includes a receiver asserting a photon received signal in response to detection of light that has reflected off a target and returned to the time-of-flight ranging system. A first latch circuit has first and second data inputs receiving a first pair of differential timing references, the first latch circuit latching data values at its first and second data inputs to first and second data outputs based upon assertion of the photon received signal. A first counter counts latching events of the first latch circuit during which the first data output is asserted, and a second counter counts latching events of the first latch circuit during which the second data output is asserted. Processing circuitry determines distance to the target based upon counted latching events output from the first and second counters.

Abstract: In an embodiment, a method includes: providing a gray-coded time reference to a time-to-digital converter (TDC); receiving an event from an event signal; latching the gray-coded time reference into a memory upon reception of the event signal; and updating a time-of-flight (ToF) histogram based on the latched gray-coded time reference.

Abstract: A distance from an apparatus to at least one object is determined by generating a first signal and generating light modulated by the first signal to be emitted from the apparatus. Light reflected by the at least one object is detected using a Time-of-flight detector array, wherein each array element of the Time-of-flight detector array generates an output signal from a series of photon counts over a number of consecutive non-overlapping time periods. The output signals are compared to the first signal to determine at least one signal phase difference. From this at least one signal phase difference a distance from the apparatus to the at least one object is determined.

Abstract: A single photon avalanche diode based range detecting apparatus includes a reference array of single photon avalanche diodes configured to receive light from an illumination source via an internally coupled path. A return array of single photon avalanche diodes is configured to receive light from the illumination source via an external free space path. A calibration pulse generator is configured to generate a calibration signal pulse. Readout circuitry is configured to receive an output of the reference array via a reference signal path, an output of the return array via a return signal path, and an output of the calibration pulse generator via a calibration signal path. The readout circuitry is configured to determine a delay difference value between the reference signal path and the return signal path based on the output of the calibration pulse generator via the calibration signal path.