# US 2025/0147159 A1 · Method and device for controlling sensitivity of a spad macro-cell > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0147159 A1 - Document ID: US20250147159A1 - Status: Published application - Kind: A1 - Application number: 18/838,535 - Filed: 2023-02-02 - Published: 2025-05-08 - Earliest claimed: 2022-04-22 - Assignees: ams-OSRAM AG - Applicants: ams-OSRAM AG - Inventors: Scott LINDNER; Michael BOEHM; Pierre-Yves TALOUD - Web page: https://patentgrep.com/patent/US20250147159A1 ## CPC - G01S 7/4863: Detector arrays, e.g. charge-transfer gates - G01S 17/10: using transmission of interrupted, pulse-modulated waves (determination of distance by phase measurements G01S17/32) - G01S 17/894: Three-dimensional [3D] imaging with simultaneous measurement of time-of-flight at a two-dimensional [2D] array of receiver pixels, e.g. time-of-flight cameras or flash lidar - 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 SPAD macro-cell comprises an array of SPAD unit, each of which comprises a SPAD and a quenching circuit for the SPAD, a combination tree to combine output signals from the SPAD units and a time-to-digital converter (TDC) operably connected to an output of the combination tree. The SPAD macro-cell is divided to a plurality of sub-cells. The SPAD macro-cell further comprises a control circuit configured to enable at least one or some SPAD units in each sub-cell in a time period and enable another one or some other SPAD units in each sub-cell in the next time period. ## Claims ### Claim 1 A SPAD macro-cell, comprising: an array of SPAD unit, each of which comprises a SPAD and a quenching circuit for the SPAD; a combination tree to combine output signals from the SPAD units; and a time-to-digital converter (TDC) operably connected to an output of the combination tree; characterized in that, the SPAD macro-cell is divided to a plurality of sub-cells; and the SPAD macro-cell further comprises a control circuit configured to enable at least one or some SPAD units in each sub-cell in a time period and enable another one or some other SPAD units in each sub-cell in the next time period. ### Claim 2 (depends on 1) The SPAD macro-cell according to claim 1, wherein the control circuit is configured to enable each SPAD unit at least once after at least two time period. ### Claim 3 (depends on 1) The SPAD macro-cell according to claim 1, wherein the control circuit is configured to enable a SPAD unit by reducing excess bias across a SPAD comprised in the SPAD unit. ### Claim 4 (depends on 1) The SPAD macro-cell according to claim 1, wherein each SPAD unit further comprises a buffer operably connected to an output of the SPAD; the control circuit is configured to enable the SPAD unit by enabling the buffer comprised in the SPAD unit. ### Claim 5 (depends on 4) The SPAD macro-cell according to claim 4, wherein the control circuit comprises a register to store a string of binary bits, each of which represents a starting status of a SPAD; and a barrel shifter to perform a logical shift operation on the string of binary bits and control the buffer based on the shift operation. ### Claim 6 (depends on 5) The SPAD macro-cell according to claim 5, wherein the control circuit further comprises a counter operably connected to the barrel shifter to control the shift operation. ### Claim 7 (depends on 6) The SPAD macro-cell according to claim 6, wherein the counter is driven by a reference clock which is the same as a laser pulse period. ### Claim 8 (depends on 5) The SPAD macro-cell according to claim 5, wherein the control circuit comprises a shift register with the same number of flip-flops as SPADs, an output of which is looped to an input which is initialized with the string of binary bits and then clocked every period. ### Claim 9 (depends on 1) The SPAD macro-cell according to claim 1, wherein the combination tree is a OR tree or XOR tree. ### Claim 10 (depends on 1) The SPAD macro-cell according claim 1, wherein the time period is a laser pulse period. ### Claim 11 (depends on 1) A SPAD detector comprises at least one SPAD macro-cell according to claim 1. ### Claim 12 (depends on 11) The SPAD detector according to claim 11, wherein the control circuit is configured to enable each SPAD unit at least once after at least two time period; SPADs in the first SPAD macro-cell present a first enable pattern at a time period, and SPADs in the second SPAD macro-cell present a second enable pattern which is different from the first enable pattern at the same time period. ### Claim 13 A method for controlling sensitivity of a SPAD macro-cell comprising an array of SPAD units, wherein the SPAD macro-cell is divided to a plurality sub-cells, a combination tree to combine output signals from the SPAD units; and a time-to-digital converter (TDC) operably connected to an output of the combination tree; characterized in that, the method comprises enabling at least one or some SPAD units in each sub-cell at a time period; and enabling another one or some other SPAD units in each sub-cell in the next time period. ### Claim 14 (depends on 13) The method according to claim 13, wherein enabling a SPAD by reducing excess bias across it. ### Claim 15 (depends on 13) The method according to claim 13, wherein enabling a SPAD unit by turning on a buffer operably connected to the SPAD. ### Claim 16 (depends on 15) The method according to claim 15, wherein the method further comprises: storing in a register a string of binary bits, each of which represents a starting enable status of a SPAD; performing a logical shift operation on the string of binary bits and control the buffers based on the shift operation through a barrel shifter. ### Claim 17 (depends on 16) The method according to claim 16, wherein the method further comprises: controlling the shift operation by a counter. ### Claim 18 (depends on 17) The method according to claim 17, wherein the counter is driven by a reference clock which is the same as reference clock of TDC. ### Claim 19 (depends on 13) The method according to claim 13, wherein the method comprises determining a number of SPAD units to be enabled by two steps: a) varying a real ambient event rate, Rra, at a detector and recording a measured ambient event rate, Rma, a pile-up factor Fpa due to the ambient illumination is then decided by Fpa=Rma/Rra; b) calculating a real signal rate Rrs according to a measured signal rate Rms and the Pile-up factor Fpa. ### Claim 20 (depends on 19) The method according to claim 19, wherein the method comprises comparing the real signal rate Rrs and a set limit to decide whether the number of SPAD units enabled in a laser pulse cycle is optimal.