An array single photon avalanche photodiode gain adaptive adjustment circuit

Abstract

The invention discloses an array single photon avalanche photodiode gain self-adaptive adjustment circuit, comprising: a current bias circuit for providing equal current for each SPAD pixel unit; a current monitoring circuit composed of a current mirror circuit for Judging its working state according to the monitored SPAD pixel unit current, and outputting different voltage signals for gain control of the SPAD pixel unit and as the input signal of the active quenching circuit; the active quenching circuit is used to monitor the output voltage of the circuit according to the current The signal generates and outputs a pulse signal to control the conduction of the quenching tube to quench the avalanche signal and prepare for the arrival of the next detection photon. The invention adopts a current mode control method to adaptively adjust the reverse bias voltage of the SPAD, overcomes the disadvantage of complex control in the traditional voltage mode mode, is suitable for array application, is easy to expand, and realizes array single photon avalanche photodiode gain consistency detection.

Description

technical field [0001] The invention relates to an array single-photon avalanche photodiode gain adaptive adjustment circuit, which belongs to the technical field of single-photon detection. Background technique [0002] The avalanche photodiode (APD) working in Geiger mode has the ability to detect single photons, so it can also be called single photon avalanche photodiode (SPAD), which is the most practical single photon detector. Single-photon detection technology can detect extremely weak optical signals, and it can be applied in medical diagnosis, astronomical observation, national defense and military, spectral measurement, quantum electronics and other fields. Currently, single photon detectors are developing towards integration and arraying. [0003] Due to the discreteness of the process, the reverse breakdown voltage of the detector is inconsistent. Therefore, in SPAD array applications, if each SPAD pixel unit is powered uniformly, it will lead to inconsistent o...

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Problems solved by technology

[0005] In order to overcome the inconsistency of the array SPAD reverse breakdown voltage caused by the discreteness of the process and solve the problem of complex design of the voltage mode reverse bias voltage adjustment circuit, an array single photon avalanche photodiode gain adaptive adjustment circuit is provided. The idea of ​​current mode reverse bias voltage adjustment realizes the adaptive adjustment of array SPAD gain, which greatly simplifies the complexity of circuit design and reduces the number of external control pins and chip area required

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