# US 11,029,396 B1 · Multiplexed multichannel photodetector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,396 B1 - Document ID: US11029396B1 - Status: Granted - Kind: B1 - Application number: 16/262,713 - Filed: 2019-01-30 - Granted: 2021-06-08 - Earliest claimed: 2015-03-26 - Assignees: Waymo LLC - Applicants: Waymo LLC - Inventors: Pierre-Yves Droz; Samuel William Lenius - Web page: https://patentgrep.com/patent/US11029396B1 ## CPC - G01S 7/4861: Circuits for detection, sampling, integration or read-out - G01S 7/484: Transmitters - G01S 7/4865: Time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak (peak detection in noise, signal conditioning G01S7/487) - G01S 7/497: Means for monitoring or calibrating - G01S 17/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) - G01S 17/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) - H04N 25/40: Extracting pixel data from image sensors by controlling scanning circuits, e.g. by modifying the number of pixels sampled or to be sampled - H04N 25/77: Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components - H04N 25/772: comprising A/D, V/T, V/F, I/T or I/F converters - H04N 25/773: comprising photon counting circuits, e.g. single photon detection [SPD] or single photon avalanche diodes [SPAD] - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A light detection and ranging (LIDAR) system can emit light toward an environment and detect responsively reflected light to determine a distance to one or more points in the environment. The reflected light can be detected by a plurality of plurality of photodiodes that are reverse-biased using a high voltage. Signals from the plurality of reverse-biased photodiodes can be amplified by respective transistors and applied to an analog-to-digital converter (ADC). The signal from a particular photodiode can be applied to the ADC by biasing a respective transistor corresponding to the particular photodiode while not biasing transistors corresponding to other photodiodes. The gain of each photodiode/transistor pair can be controlled by adjusting the bias voltage applied to each photodiode using a digital-to-analog converter. The gain of each photodiode/transistor pair can be controlled based on the detected temperature of each photodiode. ## Claims ### Claim 1 A light detection and ranging (LIDAR) system comprising: a light emitter disposed on a printed circuit board, wherein the light emitter is configured to emit a pulse of illumination light; a light detector disposed on the printed circuit board, wherein the light detector is configured to detect a light pulse and generate an output signal indicative of the detected light pulse, and wherein the detected light pulse corresponds to a reflected portion of the pulse of illumination light that is reflected from a particular location in an environment illuminated by the pulse of illumination light; a light emitter driver disposed on the printed circuit board and coupled to the light emitter; an amplifier disposed on the printed circuit board, wherein the amplifier is configured to amplify the output signal generated by the light detector; an analog-to-digital converter (ADC) disposed on the printed circuit board, wherein the ADC is configured to convert the amplified output signal to a digital signal; a channel selector disposed on the printed circuit board, wherein the channel selector is configured to select the amplifier to amplify the output signal generated by the light detector; and optics configured to collimate light emitted by the light emitter and focus light onto the light detector. ### Claim 2 (depends on 1) The LIDAR system of claim 1, further comprising: a computing device configured to: receive the digital signal indicative of the detected light pulse; and determine a time-of-flight of the pulse of illumination light from the LIDAR system to the particular location in the environment and back to the LIDAR system based on the digital signal. ### Claim 3 (depends on 1) The LIDAR system of claim 1, wherein the light emitter driver is configured to cause the light emitter to emit the pulse of illumination light. ### Claim 4 (depends on 1) The LIDAR system of claim 1, wherein two or more components of the LIDAR system are integrated onto a single integrated circuit (IC) substrate. ### Claim 5 (depends on 4) The LIDAR system of claim 4, wherein the two or more components integrated onto the single IC substrate include the light emitter and the light emitter driver. ### Claim 6 A method comprising: emitting a pulse of illumination light from a light emitter disposed on a printed circuit board, wherein the light emitter is coupled to a light emitter driver disposed on the printed circuit board; collimating, by optics, the pulse of illumination; detecting a light pulse using a detector disposed on the printed circuit board, wherein the detected light pulse corresponds to a reflected portion of the pulse of illumination light that is reflected from a particular location in an environment illuminated by the pulse of illumination light and focused onto the detector by the optics; generating an output signal indicative of the detected light pulse; selecting, via a channel selector disposed on the printed circuit board, an amplifier disposed on the printed circuit board to amplify the output signal generated by the light detector; amplifying the output signal using the amplifier disposed on the printed circuit board; and converting the amplified output signal to a digital signal using an analog-to-digital converter (ADC) disposed on the printed circuit board. ### Claim 7 (depends on 6) The method of claim 6, wherein emitting the pulse of illumination light comprises causing, via the light emitter driver, the light emitter to emit the pulse of illumination light. ### Claim 8 (depends on 6) The method of claim 6, further comprising: determining a time-of-flight of the pulse of illumination light from the LIDAR system to the particular location in the environment and back to the LIDAR system based on the digital signal. ### Claim 9 (depends on 6) The method of claim 6, wherein the light emitter and the light emitter driver are integrated onto a single integrated circuit (IC) substrate. ### Claim 10 A system comprising: a light detection and ranging (LIDAR) device configured to scan an environment of the system, the LIDAR device comprising: a light emitter disposed on a printed circuit board, wherein the light emitter is configured to emit a pulse of illumination light; a light detector disposed on the printed circuit board, wherein the light detector is configured to detect a light pulse and generate an output signal indicative of the detected light pulse, and wherein the detected light pulse corresponds to a reflected portion of the pulse of illumination light that is reflected from a particular location in the environment; a light emitter driver disposed on the printed circuit board and coupled to the light emitter; an amplifier disposed on the printed circuit board, wherein the amplifier is configured to amplify the output signal generated by the light detector; an analog-to-digital converter (ADC) disposed on the printed circuit board, wherein the ADC is configured to convert the amplified output signal to a digital signal; a channel selector disposed on the printed circuit board, wherein the channel selector is configured to select the amplifier to amplify the output signal generated by the light detector; and optics configured to collimate light emitted by the light emitter and focus light onto the light detector. ### Claim 11 (depends on 10) The system of claim 10, wherein the light emitter and the light emitter driver are integrated onto a single integrated circuit (IC) substrate. ### Claim 12 (depends on 10) The system of claim 10, further comprising: one or more processors; and data storage storing instructions that, when executed by the one or more processors, cause the system to perform operations, wherein the operations comprise operating the LIDAR device. ### Claim 13 (depends on 12) The system of claim 12, further comprising a vehicle, wherein the LIDAR device is mounted to the vehicle. ### Claim 14 (depends on 13) The system of claim 13, wherein the operations further comprise operating the vehicle in an autonomous mode based at least in part on data from the LIDAR device. ### Claim 15 (depends on 13) The system of claim 13, wherein the operations further comprise: generating a map of the environment based on data from the LIDAR device; and navigating the vehicle in the environment based at least in part on the generated map. ### Claim 16 (depends on 14) The system of claim 14, wherein the data from the LIDAR device includes the digital signal. ### Claim 17 (depends on 1) The LIDAR system of claim 1, further comprising: a digital-to-analog converter (DAC) disposed on the printed circuit board and coupled to the light detector. ### Claim 18 (depends on 1) The LIDAR system of claim 1, further comprising: a capacitor disposed on the printed circuit board, wherein the light detector is coupled to the amplifier via the capacitor. ### Claim 19 (depends on 1) The LIDAR system of claim 1, further comprising: a Schottky diode disposed on the printed circuit board; and a resistor disposed on the printed circuit board, wherein the Schottky diode and resistor are coupled in parallel between the amplifier and the channel selector.