US 12,174,064 B2
Circuit for high-sensitivity radiation sensing
Rajesh Gupta, Eindhoven (NL); Ravi Kumar Adusumalli, Eindhoven (NL); Robert Van Zeeland, Eindhoven (NL); and Rahul Thottathil, Eindhoven (NL)
Assigned to AMS-OSRAM AG, Premstaetten (AT)
Appl. No. 18/267,725
Filed by ams-OSRAM AG, Premstaetten (AT)
PCT Filed Dec. 8, 2021, PCT No. PCT/EP2021/084872
§ 371(c)(1), (2) Date Jun. 15, 2023,
PCT Pub. No. WO2022/128700, PCT Pub. Date Jun. 23, 2022.
Claims priority of application No. 2019768 (GB), filed on Dec. 15, 2020.
Prior Publication US 2024/0102857 A1, Mar. 28, 2024
Int. Cl. G01J 1/44 (2006.01); G01R 19/00 (2006.01)
CPC G01J 1/44 (2013.01) [G01R 19/0084 (2013.01); G01J 2001/446 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A circuit for sensing radiation, the circuit comprising:
a first transistor configurable to reset a voltage-level at a circuit node to a voltage reference;
measurement circuitry configured to measure the voltage-level at the circuit node;
at least one photodiode configured to vary the voltage-level at the circuit node in response to radiation incident upon the photodiode during an integration period;
processing circuitry configured to control the first transistor to reset the voltage-level at the circuit node and to subsequently configure the measurement circuitry to measure the voltage-level at a start and at an end of the integration period;
a second transistor controlled by the processing circuitry and configurable to isolate the at least one photodiode from the measurement circuitry;
an error amplifier circuit configured to minimize a bias across the at least one photodiode; and
a third transistor, wherein an output of the error amplifier circuit is coupled to a gate of the third transistor, a source of the third transistor is coupled to a cathode of the at least one photodiode, and a drain of the third transistor is coupled to the circuit node.