System and method for pixel switch switching in focal plane array

Abstract

Systems and methods for optical processing are described. According to some aspects, an optical processing device may include a pixelated photodiode array (PDA), each pixel in the PDA including a radiation detector. The apparatus also includes a readout integrated circuit (ROIC) including a logic circuit and a plurality of switching elements. The plurality of switching elements are switchable between a standby state for deactivating a corresponding radiation detector and transmitting a signal received from the corresponding radiation detector to the ROIC, and a de-standby state for de-deactivating the corresponding radiation detector and blocking the transmission of the signal, the plurality of switching elements being switchable between a standby state for deactivating the corresponding radiation detector and transmitting the signal to the ROIC, and a de-standby state for de-deactivating the corresponding radiation detector and blocking the transmission of the signal. In the standby state, the PDA is configured to detect an incident light signal, and in the de-standby state, the PDA is configured to ignore the incident light signal. In addition, the logic circuit controls a switching state of a selectable switching element associated with the radiation detector.

Description

Technical Field

[0001] The present disclosure relates generally to the operation of focal plane arrays (FPAs). More specifically, the present disclosure relates to systems and methods for improving the performance of FPAs having non-functional elements that can severely impact overall performance and product yield. Background Art

[0002] Modern vehicles can be configured to operate in an autonomous driving mode, in which the vehicle navigates in an environment with little or no input from the driver. Such an autonomous vehicle may include one or more sensors that detect information about the environment in which the vehicle operates. An autonomous vehicle (AV) and its associated computer-implemented controller use the detected information to navigate in the environment. For example, if the sensor detects that the AV is approaching an obstacle as determined by the computer-implemented controller, the controller adjusts the directional control of the AV to navigate around the obstacle. Therefore, autonomous driving navigation relies heavily on the vehicle sensors to accurately detect and map the environmental conditions encountered by the AV. One such sensor is a light detection and ranging (lidar) device. The lidar device actively estimates the distance to environmental features while scanning the scene to collect point cloud positions indicating the three-dimensional shape of the environmental scene. The various points are measured by generating laser pulses and detecting return pulses reflected from environmental objects (if any), and determining the distance to the reflecting object based on the time delay between the transmitted pulse and the received reflected pulse. Other sensors may include infrared (IR) sensors and other imaging sensors (e.g., focal plane arrays (FPAs)) that provide data points to enable autonomous driving navigation.

[0003] FPAs are image sensors consisting of an array of light-sensing elements (e.g., pixels) in the focal plane of a lens. FPAs can be used for imaging purposes (e.g., taking photos or video images) as well as non-imaging purposes such as spectroscopy, wavefront sensing, LiDAR, and other sensor applications. Summary of the invention Technical issues

[0004] Limitations in the manufacture of semiconductor devices (e.g., III-V semiconductor devices, such as FPAs) often result in some poorly performing devices on a manufactured wafer. When a device consists of many identical units (e.g., pixels in an FPA), poorly performing units can severely impact the yield of a given wafer and the overall performance of the sensor. For example, a typical FPA may consist of a photodiode array (PDA) and a readout integrated circuit (ROIC). In some aspects, the ROIC controls the arming and de-arming of the PDA. In current FPA designs, the ROIC arming bias is applied to all pixels of the FPA, including noisy pixels that have poor performance and may degrade the performance of other nearby pixels. Therefore, improving the performance of FPAs with non-functional units (e.g., non-functional pixels) is critical to the operation of the FPA, thereby improving the detection capabilities of individual sensors and the autonomous driving navigation of AVs. The systems and methods of the present disclosure address the above-mentioned problems. Technical Solution

[0005] According to various aspects, systems and methods for selectively controlling arming and de-arming operations in a pixelated photodiode array (PDA) are disclosed herein. According to some aspects, a device (e.g., an optical processing device) is disclosed, the device including a PDA, wherein each pixel in the PDA includes a radiation detector. According to some aspects, the device also includes a readout integrated circuit (ROIC), the readout integrated circuit including: a plurality of switch elements, each switch element connected to a respective radiation detector of each pixel, each switch element of the plurality of switch elements can be switched between an arm state and a de-armed state, the arm state is used to arm its corresponding radiation detector and receive an output signal from its corresponding detector, and the de-armed state is used to de-arm its corresponding radiation detector and block the output signal, wherein in the arm state, the PDA is configured to detect an input light signal, and in the de-armed state, the PDA is configured to ignore the input light signal. The ROIC also includes a logic circuit configured to control the switch state of each of the plurality of switch elements.

[0007] Additionally, the logic circuit is configured to arm the PDA and, in response to detecting a faulty operation of the radiation detector, place a first switch element of the plurality of switch elements associated with the first radiation detector into a de-armed state.

[0008] Additionally, the PDA includes one or more Geiger-mode avalanche photodiodes (GmAPDs).

[0009] Furthermore, the logic circuit is configured to place a first switching element of the plurality of switching elements associated with the first radiation detector in a de-armed state by applying a net reverse voltage value below a detected breakdown voltage of the one or more GmAPDs.

[0010] In addition, the logic circuit is also configured to place a second switching element associated with the second radiation detector among the multiple switching elements in a standby state by increasing the reverse voltage value to a bias level higher than the breakdown voltage of the detected one or more GmAPDs, and the first switching element is different from the second switching element.

[0011] Furthermore, the logic circuit is further configured to determine an operational state of each respective radiation detector, wherein the determined operational state corresponds to a selection / deselection map stored for each respective radiation detector.

[0012] Furthermore, the operational state corresponds to an observed dark current value that is above a predetermined dark current threshold.

[0013] Furthermore, the operating state corresponds to an observed noise level being above a predetermined noise threshold.

[0014] Furthermore, the operational state corresponds to an observed leakage current level that is above a predetermined leakage current threshold.

[0015] Additionally, the apparatus includes a circuit fuse configured to electrically isolate each respective radiation detector.

[0016] Additionally, the circuit fuse is configured to electrically isolate each respective radiation detector in response to operation of the radiation detector being associated with an observed leakage current above a predetermined leakage current threshold.

[0017] Additionally, circuit fuses are included within the ROIC.

[0018] In addition, the circuit fuse includes: a pair of transistors configured to control a voltage across the circuit fuse, wherein the logic circuit is further configured to apply a predetermined voltage to the pair of transistors, the predetermined voltage causing the fuse to blow and create a permanent disconnection between the PDA and the ROIC.

[0019] Additionally, the logic circuit is further configured to apply a predetermined voltage in response to the observed leakage current being above a predetermined leakage current threshold.

[0020] According to some aspects, a method is disclosed, including: receiving an optical signal at a pixelated photodiode array (PDA); arming a radiation detector of a pixel in the PDA by controlling a selectable switching element in a readout integrated circuit (ROIC) connected to the PDA by a logic circuit to power the radiation detector and transmit an output signal received by the radiation detector; and de-arming the radiation detector of the pixel in the PDA by controlling the selectable switching element by the logic circuit to disconnect the radiation detector from the power supply and prevent the radiation detector from outputting a signal.

[0021] Additionally, the method includes de-arming the radiation detector by applying a net reverse voltage value that is less than the detected breakdown voltage of the radiation detector.

[0022] Additionally, the method includes arming the radiation detector by increasing the reverse voltage value to a bias level above a breakdown voltage of the radiation detector.

[0023] Additionally, the method includes permanently disconnecting a radiation detector associated with the detected operation using a circuit fuse.

[0024] Additionally, the method includes the detected operation being a faulty operation of the radiation detector.

[0025] According to some aspects, a readout integrated circuit (ROIC) is disclosed, comprising: a plurality of switch elements connected to respective radiation detectors in a pixelated photodiode array (PDA), each of the plurality of switch elements being switchable between an armed state and a de-armed state, wherein the armed state is used to arm its corresponding radiation detector and transmit a signal received from the corresponding detector to the ROIC, and the de-armed state is used to de-arm its corresponding radiation detector and prevent signal transmission, wherein in the armed state, the PDA is configured to detect an incident light signal, and in the de-armed state, the PDA is configured to ignore the incident light signal; and a logic circuit configured to control the switch state of each of the plurality of switch elements. An optical processing device is disclosed, comprising a readout integrated circuit (ROIC). BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are incorporated herein and constitute a part of the specification.

[0027] Figure 1 An exemplary autonomous vehicle system according to aspects of the present disclosure is shown.

[0028] Figure 2 An exemplary structure of a vehicle according to aspects of the present disclosure is shown.

[0029] Figure 3An exemplary structure of a lidar system according to aspects of the present disclosure is shown.

[0030] Figure 4 Example schematic switch structures of pixel ON / OFF switches according to aspects of the present disclosure are shown.

[0031] Figure 5 A fuse assembly according to aspects of the present disclosure is shown.

[0032] Figure 6 A fuse assembly according to aspects of the present disclosure is shown.

[0033] Figure 7 Exemplary methods for selectively arming / de-arming underperforming pixels in accordance with aspects of the present disclosure are shown.

[0034] In the drawings, like reference numbers generally refer to like or similar elements. In addition, usually, the leftmost digit(s) of a reference number identifies the drawing in which the reference number first appears. DETAILED DESCRIPTION

[0035] The development and mass production of autonomous vehicles (AVs) has the potential to revolutionize transportation mobility and safety. AVs use a combination of sensors (such as radar, lidar, sonar, GPS, odometers, and inertial measurement devices) to perceive their surroundings. In some aspects, advanced control systems can interpret the sensory information to identify appropriate navigation paths and detect obstacles and related landmarks.

[0036] One key sensor that AVs rely on is lidar, which relies on systems and methods for determining distance by pointing a laser at an object and measuring the time it takes for the reflected light to return to a receiver. In accordance with some aspects, lidar can be used to make a digital 3-D representation of an area of ​​a perception area (e.g., an area surrounding an AV). Within the 3-D representation (also referred to as a lidar grid), a lidar computing system or an onboard computing device (such as computing device 220 discussed below) can detect moving objects within the perception area, can generate one or more possible object trajectories for the detected objects and the AV, and can analyze the possible object trajectories to assess the probability of collision between the objects and the AV. The performance and accuracy of the sensor system, including lidar, enables the AV to successfully navigate a route without being affected by obstacles. To do this, the hardware components that make up sensors like lidar need to operate at optimal performance.

[0037] Manufacturing sensors (e.g., LiDAR) may include acceptable tolerances for poorly performing parts. For example, limitations in the manufacturing of semiconductor devices (e.g., III-V semiconductor devices such as FPAs) often result in some poorly performing devices on a manufactured wafer. In other words, a manufactured FPA may include many poorly performing pixels, which may affect the overall performance of the FPA, thereby affecting the overall performance of the sensor (e.g., LiDAR) and autonomous driving navigation operations.

[0038] When manufacturing FPAs, manufacturers may discover that many FPAs have a large number of poorly performing elements (e.g., noise, leakage, or non-functional pixels) that may degrade the performance of the FPA. Typically, such a discovery results in the manufacturer either discarding such FPAs (thereby significantly reducing production yields) or deploying the FPAs in the field (thereby resulting in reduced detection accuracy and poor sensor performance). To address these issues, the present disclosure provides systems and methods for selectively turning poorly performing elements on and off. It will be appreciated that such a system can be deployed during manufacturing (e.g., during testing) or in the field (e.g., during operation).

[0039] According to aspects of the present disclosure, systems and methods are provided for improving object detection by selectively managing arming and de-arming operations at a per-pixel level in an FPA. This enables the system to temporarily or permanently disable poorly performing pixels that can adversely affect and degrade the performance of other nearby pixels. The benefits provided by the embodiments discussed herein reduce processing time and bandwidth, and can further enable the onboard computing device 220 to generate faster object trajectories. This is particularly important for AVs operating in the field, as faster, more accurate detection and decision-making capabilities (due to the reduction in processing time and bandwidth) can help the AV generate and execute faster navigation-based decisions, thereby improving the operation of the AV. As also mentioned herein, the reduction in processing time and bandwidth also improves power consumption, thereby increasing the overall range of, for example, a battery-powered AV.

[0040] As can be appreciated, the techniques described herein provide several advantages over existing systems. For example, existing systems provide global biasing of all PDA pixels to the same standby state. In this case, poorly performing pixels (e.g., noisy pixels) generate parasitic electrical noise that degrades the performance of nearby pixels (which would otherwise function normally). As described in the present disclosure, the ability to selectively disable noisy pixels provides a higher performance FPA and also results in a higher yield of FPA modules for manufacturers. In some aspects, noisy pixels can be selectively disabled during the test phase during module assembly or in the field. As will be further described herein, the present disclosure also provides a fuse circuit that can allow noisy pixels to be selectively disconnected from a direct current (DC) bias. This provides a corrective measure for FPAs that produce poorly performing pixels when deployed in operation. For example, in the event that an FPA is deployed in an AV and performance degradation is detected, the noisy pixels can be selectively and permanently disconnected from the DC bias so as not to provide any leakage current and / or noise signals. This performance improvement provides benefits to manufacturers and system integrators. For example, a manufacturer can achieve a higher yield of FPA modules by utilizing the selective biasing techniques described herein (rather than discarding the FPA). Additionally, system integrators integrating FPAs in the field (e.g., in LiDAR systems or other sensors) can also extract higher performance from each deployed FPA by utilizing selective biasing techniques to suppress spurious data generated by noisy pixels. This, in turn, improves the detection capabilities of the sensor (e.g., LiDAR), thereby improving the speed, accuracy, and safety of autonomous driving navigation.

[0041] The following may be an example description of a solution (autonomous driving vehicle and associated sensors) incorporating the systems and methods described herein. Those skilled in the art will appreciate that such examples are not limiting and other sensors and other applications in the solution may also be deployed.

[0042] According to some aspects, the term "vehicle" refers to any mobile form of transportation capable of carrying one or more human passengers and / or cargo and powered by any form of energy. The term "vehicle" includes, but is not limited to, cars, trucks, vans, trains, autonomous vehicles, airplanes, drones, etc. An "autonomous vehicle" (or "AV") is a vehicle having a processor, programming instructions, and drivetrain components that can be controlled by the processor without the need for a human operator. An autonomous vehicle can be fully autonomous in that it does not require a human operator to complete most or all driving conditions and functions, or it can be semi-autonomous in that a human operator may be required under certain conditions or for certain operations, or a human operator can override the vehicle's autonomous driving system and can take control of the vehicle.

[0043] It is worth noting that the present solution is described herein in the context of an autonomous vehicle. However, the present solution is not limited to autonomous vehicle applications. The present solution can be used in other applications, such as robotic applications, radar system applications, measurement applications, and / or system performance applications. It is understood that the embodiments used herein describe aspects of the present solution. It is also understood that all embodiments are exemplary and can be combined with other embodiments.

[0044] Figure 1 An exemplary autonomous vehicle system 100 according to aspects of the present disclosure is shown. The system 100 includes a vehicle 102a that travels along a road in a semi-autonomous or autonomous manner. The vehicle 102a is also referred to herein as an autonomous vehicle (AV) 102a. The AV 102a may include, but is not limited to, a land vehicle (e.g., Figure 1 shown), aircraft or vessel.

[0045] The AV 102a is generally configured to detect objects 102b, 114, and 116 in its vicinity. Objects may include, but are not limited to, vehicles 102b, riders 114 (e.g., riders of bicycles, electric scooters, motorcycles, etc.), and / or pedestrians 116. When such detection is performed, the AV 102a performs operations to generate one or more possible object trajectories of the detected object, and analyzes at least one of the generated possible object trajectories to determine whether the probability of a collision between the AV and the object reaches an undesirable level within a threshold time period (e.g., 1 minute). This may also be referred to as a collision probability assessment hereinafter. If so, the AV 102a performs operations to determine whether the collision can be avoided if the AV 102a follows a given vehicle trajectory and performs any one of a plurality of dynamically generated emergency maneuvers within a predefined time period (e.g., N milliseconds). If the collision can be avoided, the AV 102a takes no action or optionally performs a cautious maneuver (e.g., moderate deceleration). Conversely, if the collision cannot be avoided, the AV 102a immediately takes an emergency maneuver (e.g., braking and / or changing the direction of travel). Those skilled in the relevant art will appreciate that other methods of collision detection and avoidance by the AV 102a are contemplated by the present disclosure.

[0046] If combined Figure 3In more detail, the AV 102a can be configured with a laser radar system 300. The laser radar system 300 can include a light transmitter system 304 (transmitter) that transmits light pulses 104 to detect objects within a distance or range of the AV 102a. The light pulses 104 can be incident on one or more objects (e.g., AV 102b) and reflected back to the laser radar system 300. The reflected light pulses 106 incident on the light detector 308 are processed by the laser radar system 300 to determine the distance of the object to the AV 102a. In some embodiments, the light detector 308 can include a photodetector or a photodetector array that is positioned and configured to receive light reflected back to the system. For example, the light detector 308 can include a focal plane array that includes a photodiode array (PDA) and a readout integrated circuit (ROIC). According to some aspects, each pixel of the PDA can be electrically connected to a dedicated channel of the ROIC so that the ROIC controls the arming and de-arming of each PDA pixel through an ON / OFF switch, which will be further described herein. According to some aspects, the PDA may include a Geiger-mode avalanche photodiode (GmAPD), which is capable of detecting single photon energy levels.

[0047] In some aspects, silicon photodiodes convert light into an electrical signal. This conversion occurs when a photon with energy greater than the bandgap of the detector material is absorbed, exciting an electron from the valence band of the semiconductor to the conduction band where it is read out as a signal. The GmAPD uses the same process, but the GmAPD uses an avalanche multiplication method to generate internal gain. An avalanche region is created within the APD, forming a region of very high electric field strength. When a photogenerated (or thermally generated) electron in the conduction band moves into the avalanche region, the electric field strength is sufficient to accelerate it to a point where it can cause "impact ionization" and release another electron. These two electrons can also be accelerated, resulting in avalanche multiplication. This method gives the detector gain. Typical gain for an APD is in the range of tens to several hundred.

[0048] Geiger mode operation can increase the modest gain of an APD to more significant levels. The gain of an APD increases with stronger internal electric fields, but is limited by the breakdown voltage V applied by the corresponding external b The threshold breakdown electric field E b For less than V b The output photocurrent of the APD is proportional to the input light intensity, and device operation below the breakdown voltage is referred to as "linear mode". In contrast, above V bThe applied voltage is such that there is a finite probability that a single carrier injected into the avalanche region will trigger a self-sustaining avalanche characterized by divergent (i.e., infinite) gain. This rapid generation of an easily measurable avalanche current, triggered by only a single photoexcited carrier, allows efficient detection of single photons. In actual operation, a self-sustaining Geiger-mode avalanche is quenched as soon as it is detected. In this context, the amount of charge that flows in response to a single electron injection into the avalanche region (typically >>10 5 ) gives the effective gain.

[0049] In some aspects, quenching and resetting of the GmAPD can be achieved passively by placing a sufficiently large resistor in series with the detector. A fixed bias voltage is applied across the series combination of the GmAPD and the resistor. When no current is flowing, the entire bias is dropped across the GmAPD and it is in an "armed" state. When the junction breaks down, a large current flows through the resistor and the resulting voltage drop across the resistor reduces the voltage across the GmAPD, causing the avalanche process to be passively quenched to a "disarmed" state. In other cases, when avalanche breakdown is detected, the bias voltage is actively reduced to below the breakdown voltage and the GmAPD avalanche is actively quenched. After either type of quenching reaches the "disarmed" state, the bias voltage across the GmAPD is reset to a value above the breakdown voltage so that it can be armed again for subsequent detection. The discharge and reset cycle is referred to as the Geiger mode of operation. These operations can be found in the referenced sections of this article. Figure 4-Figure 6 Further explanation.

[0050] If you will refer to Figure 4 As further discussed, aspects of the present disclosure are intended to selectively turn off pixels in an FPA so that the FPA can still perform the desired functions when operating without all of its pixels being operational. For an FPA using a GmAPD, the PDA can be armed and unarmed by manipulating the applied net reverse voltage relative to the GMAPD breakdown voltage. For example, the PDA can be considered armed when the applied net reverse voltage is higher than the breakdown voltage of the GmAPD. Similarly, the PDA can be unarmed when the applied net reverse voltage is less than the GmAPD breakdown voltage. It is understood that the PDA is considered armed by increasing the reverse voltage to a bias higher than the breakdown voltage. According to some aspects, the total voltage on the PDA can be the sum of a fixed negative DC bias voltage (Vdc) and an additional standby bias applied by the ROIC. For example, for a standby bias, in which the transistors on standby are switched between +5V and 0V (ground), the sum of the (negative) voltages (e.g., Vdc+5V) puts the PDA in an unarmed state. In other words, rather than putting the entire PDA on standby, the present disclosure enables the selective de-arming of poorly performing pixels so that the behavior of those pixels (when biased above the breakdown voltage) does not hinder the performance of neighboring pixels. Figure 4 As shown, this selective de-arming can be performed by a switch. In some cases, whether during testing or in the field of operation (e.g., in an operating sensor like a LiDAR sensor), a de-armed pixel may still generate leakage current sufficient to degrade the performance of nearby pixels. In this case, a fuse can be activated, which can permanently de-arm the non-functional pixel. Figure 5 and Figure 6 The implementation of fuses is shown separately.

[0051] continue Figure 1 , the lidar information (e.g., detected object data) is transmitted from the lidar system 300 to the onboard computing device 220 ( Figure 2 ). AV 102a may also transmit the lidar data to a remote computing device 110 (e.g., a cloud processing system) via a communication network 108. The remote computing device 110 may be configured with one or more servers to process one or more methods of the technology described herein. The remote computing device 110 may also be configured to transmit data / instructions from AV 102a to a server and / or database 112 or from a server and / or database 112 to AV 102a via the network 108.

[0052] The network 108 may include one or more wired or wireless networks. For example, the network 108 may include a cellular network (e.g., a long-term evolution (LTE) network, a code division multiple access (CDMA) network, a 3G network, a 4G network, a 5G network, another type of next-generation network, etc.). The network may also include a public land mobile network (PLMN), a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), a telephone network (e.g., a public switched telephone network (PSTN)), a private network, an ad hoc network, an intranet, the Internet, a fiber-optic-based network, a cloud computing network, etc., and / or a combination of these or other types of networks.

[0053] AV 102a may retrieve, receive, display and edit information generated from local applications or transferred from database 112 via network 108. Database 112 may be configured to store and provide raw data, indexed data, structured data, mapped data, program instructions or other configurations known in the art.

[0054] Figure 2 An exemplary system architecture 200 for a vehicle is shown in accordance with aspects of the present disclosure. Figure 1 The vehicles 102a and / or 102b may have Figure 2 Therefore, the following discussion of system structure 200 is sufficient to understand Figure 1However, other types of vehicles are considered within the scope of the technology described herein and may include, for example, a combination of Figure 2 As a non-limiting example, an air vehicle may not include brakes or gear controls, but may include an altitude sensor. In another non-limiting example, a water vehicle may include a depth sensor. Those skilled in the art will appreciate that, as is known, other propulsion systems, sensors, and controls may be included based on the type of vehicle.

[0055] like Figure 2 As shown, system architecture 200 includes an engine or motor 202 and various sensors 204-218 for measuring various parameters of the vehicle. In a gas-powered or hybrid vehicle having a fuel-powered engine, the sensors may include, for example, an engine temperature sensor 204, a battery voltage sensor 206, an engine revolutions per minute ("RPM") sensor 208, and a throttle position sensor 210. If the vehicle is an electric or hybrid vehicle, the vehicle may have an electric motor and accordingly include sensors such as a battery monitoring system 212 (to measure the current, voltage, and / or temperature of the battery), a motor current sensor 214 and a voltage sensor 216, and a motor position sensor 218 (e.g., a rotary transformer and encoder).

[0056] Operating parameter sensors common to both types of vehicles include, for example, position sensors 236 (e.g., accelerometers, gyroscopes, and / or inertial measurement units); speed sensors 238; and odometer sensors 240. The vehicle may also have a clock 242 that the system uses to determine the vehicle time during operation. The clock 242 may be encoded into an onboard computing device, which may be a separate device, or multiple clocks may be available.

[0057] The vehicle also includes various sensors for collecting information about the environment in which the vehicle is traveling and detecting objects. These sensors may include, for example, a position sensor 260 (e.g., a global positioning system ("GPS") device); one or more cameras 262; a lidar system 264; and / or a radar and / or sonar system 266. The sensors may also include environmental sensors 268, such as a precipitation sensor and / or an ambient temperature sensor. Object detection sensors may enable the vehicle to detect objects within a given distance range of the vehicle 200 in any direction, while environmental sensors collect data about environmental conditions within the area in which the vehicle is traveling.

[0058] During operation, information is transmitted from the sensors to the onboard computing device 220. The onboard computing device 220 analyzes the data captured by the sensors and optionally controls the operation of the vehicle based on the analysis results. For example, the onboard computing device 220 can control: braking via brake controller 222; direction via steering controller 224; speed and acceleration via throttle controller 226 (in a gas-powered vehicle) or motor speed controller 228 (such as a current level controller in an electric vehicle); differential gear controller 230 (in a vehicle with a transmission); and / or, other controllers. The auxiliary device controller 254 can be configured to control one or more auxiliary devices, such as a test system, auxiliary sensors, mobile equipment transported by the vehicle, etc.

[0059] The geographic location information may be transmitted from the location sensor 260 to the vehicle onboard computing device 220, which may then access a map of the environment corresponding to the location information to determine known fixed features of the environment, such as streets, buildings, stop signs, and / or stop / go signs. Images captured from the camera 262 and / or object detection information (from those sensors) captured from sensors such as lidar 264 are transmitted to the onboard computing device 220. The onboard computing device 220 processes the object detection information and / or the captured images to detect objects in the vicinity of the vehicle 200. Techniques for object detection based on sensor data and / or captured images may be used in the embodiments disclosed herein.

[0060] For example, lidar information captured by detector 308 is transmitted from lidar system 264 to onboard computing device 220. Additionally, captured images are transmitted from camera 262 to onboard computing device 220. Onboard computing device 220 processes the lidar information and / or the captured images to detect objects in the vicinity of vehicle 200. The manner in which onboard computing device 220 performs object detection includes such capabilities as described in detail in this disclosure.

[0061] As can be appreciated by those skilled in the art, by improving the detection capabilities of the lidar system 264 (more specifically, the detector 308), the vehicle onboard computing device 220 can receive more accurate detections and generate more accurate object tracks and trajectories for detected objects. This results in improved autonomous driving navigation because at least one sensor in the vehicle sensor suite is providing improved and more accurate detection information. This improvement provides additional downstream benefits. For example, because less computing bandwidth can be spent on checking sensor accuracy data, processing more accurate information can enable the vehicle onboard computing device 220 to perform analysis and provide solutions at a faster rate.

[0062] Figure 3 An exemplary structure of a laser radar system 300 according to aspects of the present disclosure is shown. In some aspects, Figure 2 The laser radar system 264 can be the same as or substantially similar to the laser radar system 300. Thus, the discussion of the laser radar system 300 is sufficient to understand Figure 2 LiDAR system 264.

[0063] like Figure 3 As shown, the laser radar system 300 includes a housing 306 that can rotate 360° about a central axis such as a hub or shaft 315 of a motor 316. The housing can include a transmitter / receiver aperture 312 made of a light-transmissive material. Figure 3 A single hole is shown in FIG, but the present solution is not limited in this regard. In other cases, multiple holes for transmitting and / or receiving light can be provided. Either way, when the housing 306 rotates about the internal components, the lidar system 300 can transmit light through one or more holes 312 and receive reflected light back toward one or more holes 212. In another case, the shell of the housing 306 can be a stationary dome, at least partially made of a light-transmissive material, with a rotatable component inside the housing 306.

[0064] Within the rotating shell or stationary dome is a light emitter system 304 that is configured and positioned to generate and emit light pulses through the hole 312 or through the transparent dome of the shell 306 via one or more laser emitter chips or other light emitting devices. The emitter system 304 may include any number of individual emitters (e.g., 8 emitters, 64 emitters, or 128 emitters). The emitters may emit light of substantially the same intensity or different intensities. The lidar system also includes a light detector 308 that includes a light detector or a light detector array (e.g., a focal plane array (FPA) including a photodiode array (PDA) and / or a Geiger mode PDA) that is positioned and configured to receive light reflected back to the system. In one example, the light emitter system 304 and the light detector 308 will rotate with the rotating shell, or they will rotate within the stationary dome of the shell 306. It will be appreciated that the mechanical lidar system described herein is merely an example lidar system upon which aspects of the present solution rely, and that other examples of lidar systems (e.g., solid-state lidar systems) may also be implemented.

[0065] In some aspects, one or more optical element structures 310 can be positioned in front of the light emitter system 304 and / or light detector 308 to act as one or more lenses or wave plates to focus and direct light passing through the optical element structures 310 .

[0066] One or more optical element structures 310 can be located in front of a mirror (not shown) to focus and direct light passing through the optical element structure 310 (e.g., such as in a focal plane array). As shown below, the system includes an optical element structure 310 located in front of the mirror, which is connected to a rotating element of the system so that the optical element structure 310 rotates with the mirror. Alternatively or additionally, the optical element structure 310 can include a plurality of such structures (e.g., lenses and / or wave plates). Optionally, a plurality of optical element structures 310 can be arranged in an array on the outer shell portion of the housing 306 or integrated with the outer shell portion of the housing 306.

[0067] According to some aspects, the lidar system 300 includes a power supply unit 318 that powers the light emitting unit 304, the motor 316, and the electronic components. The lidar system 300 also includes an analyzer 314 having elements such as a processor 322 and a non-transitory computer-readable memory 320 containing programming instructions, the programming instructions being configured to enable the system to receive data collected by the light detector unit, analyze it to measure characteristics of the received light, and generate information that a connected system can use to make decisions about operating in the environment in which the data was collected. Optionally, the analyzer 314 can be integrated with the lidar system 300 as shown, or part or all of it can be external to the lidar system and communicatively connected to the lidar system via a wired or wireless communication network or link.

[0068] In accordance with some aspects, the lidar system 300 can generate an output and provide it to a vehicle onboard computing system (e.g., the onboard computing device 220). Such an output can include a three-dimensional (3-D) map of the perception area (the area illuminated by the lidar 264 or the lidar 300). In accordance with some aspects, the three-dimensional map can also be referred to as a lidar grid, where the grid cells can each provide a scaled representation of the perception area. When an object is detected within the lidar grid, the onboard computing device 220 can attempt to generate a point cloud map (e.g., a lidar grid) that includes the detected object, and then generate a collision threat assessment and potential navigation instructions to other AV systems. Accordingly, systems and methods for improving the detection capabilities and performance of FPAs are described below with respect to Figure 4-Figure 7 Give a description.

[0069] Figure 4An exemplary schematic switch structure 400 including a pixel ON / OFF switch according to some embodiments is shown. The switch structure 400 may include a photodiode 402, a high voltage source 404, an arm / disarm control circuit 406, a disarm voltage source 408, an arm voltage source 410, and a counter stop 412. According to some aspects, the high voltage source 404 may be connected to the cathode of the photodiode 402. The photodiode 402 may be a GmAPD photodiode. According to some aspects, the arm / disarm control circuit 406 may be configured to dynamically increase the bias voltage (e.g., a high voltage power supply) to a voltage higher than the breakdown voltage of the photodiode 402. In one example, when an avalanche event occurs (e.g., when light is received), the disarm circuit extinguishes (i.e., stops) the avalanche current and triggers the counter stop mechanism. Although not shown, the arm / disarm control circuit 406 may also include a microprocessor, a central processing unit (CPU), and / or a logic circuit configured to process commands to enable the arm / disarm operation of the switch. In some aspects, to prevent the photodiode from being armed above its breakdown voltage, the arm / disarm control circuit 406 may not assert the arm control signal. Although not shown, the switch structure 400 may connect the output of the photodiode 402 to the ROIC. According to some aspects, the circuit elements connected to the anode of the photodiode 402 may be part of the ROIC (e.g., elements 406, 408, 410, and 412).

[0070] It will be appreciated that the PDA may be a pixelated photodiode array, wherein each pixel in the PDA includes a radiation detector such as photodiode 402. Figure 4 A single switch structure is shown, but it is understood that the PDA is connected to multiple switches, each switch is connected to a respective radiation detector (e.g., photodiode 402) to selectively arm and de-arm the respective photodiode 402. As described herein, the selective arming and de-arming can be based on the observed performance of each photodiode 402 in the PDA, so that photodiodes with poor performance can be selectively de-armed according to aspects of the present disclosure. It is understood that the selective arming and de-arming can also be based on the situation that the user (e.g., tester or operator) does not want to arm a particular detector because the user is not interested in data for the corresponding area in the imaging scene.

[0071] As described herein, aspects of the present invention disable poorly performing pixels (e.g., noisy pixels / noisy photodiodes) by providing an addressable pixel-level switch (e.g., switch assembly 400) that selectively prevents the noisy pixels from being armed during FPA operation. In this regard, the arm / disarm circuit 406 can maintain the arm transistor associated with the noisy pixel on its +5V rail and does not allow the transistor to be pulled down to ground. This action forces the associated PDA pixel to remain in a disarmed state. In other words, the arm / disarm circuit 406 can be configured to maintain the noisy pixel in a disarmed state with a bias voltage of Vdc+5V by preventing the arm transistor from switching from +5V to 0V (ground). In this case, the noisy pixel is always maintained at a disarmed bias of Vdc+5V. Therefore, by applying a net reverse voltage value below the breakdown voltage of the GmAPD, the switch assembly 400 prevents the noisy pixel from being armed during APD operation. To place the pixel in the standby state, the switch component 400 may apply a net reverse voltage value that is higher than the breakdown voltage of the photodiode 402 .

[0072] It will be appreciated that a given pixel may be determined to be underperforming during the testing phase, and the state of the underperforming pixel may be stored as part of a deselection map. In some aspects, the deselection map may indicate the state of each pixel in the PDA and the type of fault (if any) that may be associated with each pixel. For example, the deselection map may include a state associated with the photodiode 402, indicating that the photodiode is not working. In addition, the deselection map may also indicate that the underperforming photodiode 402 is a noisy pixel. It will be appreciated that other underperforming states may be stored in the deselection map, including but not limited to: observed dark current values ​​above a predetermined dark current threshold, and / or observed leakage current levels above a predetermined leakage current threshold. In addition, as described herein, the deselection map may also list user preferences that cause certain detectors to be removed from standby.

[0073] According to some aspects, a switch structure (eg, switch structure 400) may include a switch structure as described herein with reference to Figure 5 and Figure 6 According to some aspects, the fuse element can be incorporated as an additional element Figure 4In the switch structure described in . It will be appreciated that in some cases, even in the de-armed state, the Vdc+5V bias may produce leakage currents that degrade the performance of nearby pixels. In other words, even if the noisy pixels are eliminated, the bias voltage may cause leakage currents that degrade the performance of nearby pixels. In this case, a fuse circuit may be incorporated into the PDA or ROIC to allow the noisy pixels to be selectively disconnected from the DC bias. According to some aspects, the combination of switch and fuse elements provides certain benefits. For example, using a switch element, an operator may initially have greater freedom when selecting and deselecting pixels / detectors. This provides a more robust testing practice and increases the adaptability of the sensor and switch structure. In cases where the de-armed pixel may still affect the performance of other nearby pixels, the fuse element can be used to permanently eliminate this effect.

[0074] According to some aspects, the fuse elements described herein can be used as a replacement for switch elements. According to some aspects, using fuse elements alone can reduce the complexity of switch components and the associated processing bandwidth.

[0075] Regardless of whether the fuse element is implemented alone or in conjunction with the switch element, the operation of the fuse element is described below. According to some aspects, the fuse element can be blown, thereby permanently disconnecting the selectable pixel. According to some aspects, the blowing of the fuse can be programmed as a specific processing step after the initial testing of the FPA to identify the leaking pixel. According to some aspects, the blowing of the fuse can be a specific step that can be programmed to be performed when the leaking pixel is identified in the field. This may occur when the pixel performance degrades over time and the pixel may become a noisy pixel and / or when the leakage current of the pixel released from standby is observed in the field over time. In order to avoid replacing the entire sensor assembly of the operational AV, the fuse circuit can be blown so that the associated PDA pixel is permanently / electrically disconnected from its corresponding ROIC channel and DC bias circuit.

[0076] Figure 5 A fuse assembly 500 is shown according to some aspects. The fuse assembly 500 can include a fuse 502 placed between an APD 504 and an ROIC input 506. The fuse assembly 500 can also include a pair of transistors 508 and 510 configured to control a voltage 512 across the fuse. As described herein, the placement of the fuse allows a noisy pixel that generates a leakage current even when de-armed to be permanently disconnected from a corresponding ROIC channel and bias circuit. According to some aspects, when a voltage 512 to ground through the fuse 502 is activated, the fuse 502 will burn through, thereby creating a permanent open circuit between the APD 502 and the ROIC input 504, thereby permanently disabling the associated pixel. It will be appreciated that the fuse 502 can be an integrated component of the ROIC or PDA.

[0077] Figure 6 A fuse assembly 600 is shown according to some aspects. The fuse assembly 600 may include a fuse 602 that may be placed within the PDA (e.g., on the PDA die). In this way, an all-electric approach may be employed to disable pixels during wafer-level testing. According to some aspects, the fuse 602 may be mounted at the cathode or anode of the APD 608 (the cathode is shown herein). In some aspects, a pixel identified as leaking will be forward biased so that it draws enough current to blow the fuse. In some aspects, the fuse may be connected in series with the APD circuit or accessed with a separate pad (such as pad 604). Similar to the fuse assembly 500, when a pixel generates a leakage current to be forward biased, sufficient current will be drawn through the high voltage 606 to blow the fuse 602, thereby creating an open circuit. According to some aspects, the open circuit created by the blown fuse disconnects the APD from the DC bias and effectively disconnects the pixel that generates the leakage current. It will be appreciated that the function of the resistor 610 is to act as a quenching resistor as described herein. Passive quenching can be used in fuse assembly 600 to reduce the total avalanche current amplitude and help protect the photodiode element from high current overload in the presence of very large optical input signals. It is understood that activation of fuse 602 (e.g., blowing of the fuse) can be automatically triggered by forward bias operation of the connected pixel and / or by operation of the control circuit (e.g., circuit 400). It is understood that the control circuit can enable transistors 508 and 510 to allow a sufficiently large current from the voltage source to blow fuse 502.

[0078] Figure 7 An exemplary method 700 for performing the switching operations described herein is shown. According to some aspects, method 700 may include receiving an optical signal at a pixelated photodiode array (PDA), as shown in step 702. According to some aspects, the optical signal may be return light reflected from a surrounding surface. According to some aspects, method 700 may also include arming a radiation detector of a pixel in the PDA by controlling an optional switch element of an ROIC connected to the PDA, as shown in step 704. It will be understood that the arming may be performed by logic circuitry of the ROIC, and the optional switch may send an output signal received by the radiation detector. According to some aspects, method 700 may also include de-arming a radiation detector of a pixel in the PDA by controlling an optional switch element of the ROIC by the logic circuitry, the optional switch element being configured to prevent the radiation detector from outputting a signal, as shown in step 704. It will be understood that the arming and de-arming operations using the switch are similar to those described herein with reference to Figure 4 The operation is consistent with the description.

[0079] According to one example, when implemented in a sensor assembly (e.g., an FPA and / or a lidar sensor), the ROIC can be configured to detect the occurrence of an avalanche event, stop a pixel-level counter, and record a timestamp of the counter as an indication that the pixel has avalanched. The ROIC can also be configured to provide the exact time of the pixel avalanche, which corresponds to the time of flight of the reflected pulse returning to the pixel. The timestamps recorded from all pixels (including those recording a "terminal count" if they did not avalanche) are then read out to an external electronic device, which utilizes the "time stamp" data to generate a lidar point cloud using appropriate digital signal processing (DSP) firmware.

[0080] According to some aspects, the method may further include detecting a breakdown voltage of the GmAPD and placing different optional switching elements associated with the operable radiation element in an activated state by increasing the reverse voltage value to a bias level above the breakdown voltage of the GmAPD. According to some aspects, the method may further include storing a deselection map indicating a faulty operation of the radiation detector, and detecting the faulty operation of the radiation detector based on the deselection map. According to some aspects, the faulty operation of the radiation detector is associated with an observed dark current value greater than a predetermined dark current threshold. The faulty operation of the radiation detector may also be associated with an observed noise level above a predetermined noise threshold. It will be understood that the deselection map may store detector data, not just faulty operation. It will be understood by those skilled in the art that the deselection map may store deselection metrics associated with other physical properties of the radiation detector and / or user preferences. Such user preferences may be set for a variety of reasons, including but not limited to testing and integration purposes.

[0081] According to some aspects, the faulty operation of the radiation detector may also be associated with an observed leakage current level that is above a predetermined leakage current threshold. In this regard, the method may also include, in response to the observed leakage current being above the predetermined leakage current threshold, using a circuit fuse to separate the radiation detector associated with the detected faulty operation. The method may also include applying a predetermined voltage to a pair of transistors within the circuit fuse to blow the fuse. It is understood that the transistor is enabled to allow a sufficiently large current from a voltage source (e.g., high voltage 606 or voltage source 512) to blow the fuse. In response to the observed leakage current being above the predetermined leakage current threshold, the blown fuse creates a permanent open circuit between the PDA and the ROIC (i.e., the PDA and the ROIC are permanently separated).

[0082] It should be understood that the detailed description section (but not any other section) is intended to be used to interpret the claims. The other sections may set forth one or more but not all exemplary aspects contemplated by the inventors, and therefore, are not intended to limit the present disclosure or the appended claims in any way.

[0083] According to aspects of the present disclosure, a device may be disclosed, including: a pixelated photodiode array (PDA), wherein each pixel in the PDA includes a radiation detector; and a readout integrated circuit (ROIC). According to some aspects, the ROIC may include: a plurality of switch elements, each switch element connected to the respective radiation detector of each pixel, each of the plurality of switch elements being switchable between a standby state and a de-armed state, wherein the standby state is used to arm its corresponding radiation detector and receive an output signal from its corresponding detector, and the de-armed state is used to de-arm its corresponding radiation detector and block the output signal, wherein in the standby state, the PDA is configured to detect an incident light signal, and in the de-armed state, the PDA is configured to ignore the incident light signal; and a logic circuit configured to control the switch state of each of the plurality of switch elements.

[0084] According to some aspects, the logic circuit may be further configured to arm the PDA and, in response to detecting a faulty operation of the radiation detector, place a first switch element of the plurality of switch elements associated with the first radiation detector into a de-armed state.

[0085] According to some aspects, the PDA includes one or more Geiger-mode avalanche photodiodes (GmAPDs). According to some aspects, the logic circuit is further configured to place a first switch element associated with a first radiation detector in a de-armed state by applying a net reverse voltage value that is less than a detected breakdown voltage of the one or more GmAPDs. In addition, the logic circuit can be further configured to place a second switch element associated with a second radiation detector in a plurality of switch elements in an armed state by increasing the reverse voltage value to a bias level that is greater than a detected breakdown voltage of the one or more GmAPDs, the first switch element being different from the second switch element.

[0086] According to some aspects, the logic circuit is further configured to determine an operating state of each respective radiation detector, wherein the determined operating state corresponds to a select / deselect map stored for each respective radiation detector. According to some aspects, the operating state corresponds to an observed dark current value above a predetermined dark current threshold. According to some aspects, the operating state corresponds to an observed noise level above a predetermined noise threshold. According to some aspects, the operating state corresponds to an observed leakage current level above a predetermined leakage current threshold.

[0087] According to some aspects, the apparatus may further include a circuit fuse configured to electrically isolate each respective radiation detector. According to some aspects, the circuit fuse is configured to electrically isolate each respective radiation detector in response to operation of the radiation detector being associated with an observed leakage current greater than a predetermined leakage current threshold. According to some aspects, the circuit fuse is contained within the ROIC. It will be appreciated that the circuit fuse may include a pair of transistors configured to control a voltage across the circuit fuse, wherein the logic circuit is further configured to apply a predetermined voltage to the pair of transistors, the predetermined voltage causing the fuse to blow and creating a permanent open circuit between the PDA and the ROIC. According to some aspects, the logic circuit is further configured to apply the predetermined voltage in response to the observed leakage current being above the predetermined leakage current threshold.

[0088] Although the present disclosure describes exemplary aspects of exemplary fields and applications, it should be understood that the present disclosure is not limited thereto. Other aspects and modifications thereof are possible and are within the scope and spirit of the present disclosure. For example, without limiting the generality of this paragraph, the various aspects are not limited to the software, hardware, firmware, and / or entities shown in the drawings and / or described herein. In addition, the various aspects (whether or not explicitly described herein) have significant utility for fields and applications beyond the examples described herein.

[0089] Various aspects are described herein by means of functional building blocks that illustrate the implementation of specific functions and their relationships. For ease of description, the boundaries of these functional building blocks are arbitrarily defined herein. Alternative boundaries may be defined as long as the specified functions and relationships (or their equivalents) are properly performed. In addition, alternative aspects may use a different order than described herein to perform functional blocks, steps, operations, methods, etc.

[0090] References to "an aspect", "on the one hand", "an exemplary aspect" or similar phrases herein indicate that the described aspects may include specific features, structures or characteristics, but not every aspect must include specific features, structures or characteristics. In addition, these phrases do not necessarily refer to the same aspect. In addition, when describing specific features, structures or characteristics in conjunction with an aspect, it will be within the knowledge of those skilled in the art to combine such features, structures or characteristics to other aspects, whether or not explicitly mentioned or described in this article. In addition, some aspects can be described using the expressions "connection" and "connection" and their derivatives. These terms are not necessarily synonymous with each other. For example, some aspects can be described using the terms "connection" and / or "connection (coupling)", to indicate that two or more elements are in direct physical or electrical contact with each other. However, the term "connection" can also mean that two or more elements are not in direct contact with each other, but still cooperate or interact with each other.

[0091] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents.

[0092] It should be understood that the detailed description section (but not any other section) is intended to be used to interpret the claims. The other sections may set forth one or more but not all exemplary embodiments contemplated by the inventors, and therefore are not intended to limit the present disclosure or the appended claims in any way.

[0093] Although the present disclosure describes exemplary embodiments of exemplary fields and applications, it should be understood that the present disclosure is not limited thereto. Other embodiments and modifications thereto are possible and within the scope and spirit of the present disclosure. For example, without limiting the generality of this paragraph, the embodiments are not limited to the software, hardware, firmware and / or entities shown in the drawings and / or described herein. In addition, the embodiments (whether or not explicitly described herein) have significant utility for fields and applications beyond the examples described herein.

[0094] Embodiments are described herein with the aid of functional building blocks, which illustrate the implementation of specific functions and their relationships. For ease of description, the boundaries of these functional building blocks are arbitrarily defined herein. As long as the specified functions and relationships (or their equivalents) are properly performed, alternative boundaries can be defined. In addition, alternative embodiments can use different orders than those described herein to perform functional blocks, steps, operations, methods, etc.

[0095] References to "one embodiment," "embodiment," "example embodiment," or similar phrases herein indicate that the described embodiments may include specific features, structures, or characteristics, but not every embodiment must include specific features, structures, or characteristics. In addition, these phrases do not necessarily refer to the same embodiment. In addition, when describing specific features, structures, or characteristics in conjunction with one embodiment, it is within the knowledge of those skilled in the art to incorporate such features, structures, or characteristics into other embodiments, whether or not explicitly mentioned or described herein. In addition, some embodiments may be described using the expressions "connect" and "connect" and their derivatives. These terms are not necessarily synonymous with each other. For example, some embodiments may be described using the terms "connect" and / or "connect" to indicate that two or more elements are in direct physical or electrical contact with each other. However, the term "connect" may also mean that two or more elements are not in direct contact with each other, but still cooperate or interact with each other.

[0096] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A device comprising: a pixelated photodiode array (PDA), wherein each pixel in the PDA comprises a radiation detector; and Readout Integrated Circuit (ROIC), including: a plurality of switch elements, each switch element being connected to a respective radiation detector of each pixel, each of the plurality of switch elements being capable of switching between a standby state and a de-armed state, the standby state being used to arm the radiation detector corresponding to each of the plurality of switch elements and receive an output signal from the radiation detector corresponding to each of the plurality of switch elements, the de-armed state being used to de-arm the radiation detector corresponding to each of the plurality of switch elements and block the output signal, wherein in the standby state, the PDA is configured to detect an incident light signal, and in the de-armed state, the PDA is configured to ignore the incident light signal, and The logic circuit is configured to control a switching state of each of the plurality of switching elements.

2. The device according to claim 1, wherein: The logic circuit is further configured to: Put the PDA on standby, and In response to detecting a faulty operation of the radiation detector, a first switch element of the plurality of switch elements associated with a first radiation detector is placed in the de-armed state.

3. The device according to claim 1, wherein: The PDA includes one or more Geiger-mode avalanche photodiodes (GmAPDs).

4. The device according to claim 3, wherein: The logic circuit is further configured to: A first switching element of the plurality of switching elements associated with a first radiation detector is placed in the de-armed state by applying a net reverse voltage value below a detected breakdown voltage of the one or more GmAPDs.

5. The device according to claim 4, wherein: The logic circuit is further configured to: A second switching element associated with a second radiation detector of the plurality of switching elements is placed in the standby state by increasing a reverse voltage value to a bias level above the detected breakdown voltage of the one or more GmAPDs, the first switching element being different from the second switching element.

6. The device according to claim 1, wherein: The logic circuit is further configured to: An operational state of each respective radiation detector is determined, wherein the determined operational state corresponds to a selection / deselection map stored for each respective radiation detector.

7. The device according to claim 6, wherein: The operating state corresponds to an observed dark current value that is above a predetermined dark current threshold.

8. The device according to claim 6, wherein: The operating state corresponds to an observed noise level above a predetermined noise threshold.

9. The device according to claim 6, wherein: The operating state corresponds to an observed leakage current level that is above a predetermined leakage current threshold.

10. The apparatus according to claim 1, further comprising: A circuit fuse is configured to electrically isolate each respective radiation detector.

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