Self-adaptive adjustment circuit for gain of array single-photon avalanche photodiode

Abstract

The invention discloses a self-adaptive adjustment circuit for the gain of an array single-photon avalanche photodiode. The self-adaptive adjustment circuit comprises a current biasing circuit, current monitoring circuits and active quenching circuits; the current biasing circuit is used for providing equal current for each SPAD pixel unit; the current monitoring circuits are composed of current mirror circuits and used for judging the working states of the SPAD pixel units according to the current of the monitored SPAD pixel units and outputting different voltage signals for gain control overthe SPAD pixel units to serve as input signals of the active quenching circuits; the active quenching circuits are used for generating and outputting pulse signals according to the voltage signals output by the current monitoring circuits to control quenching tubes to be switched on so that quenching of avalanche signals is achieved to be ready for arrival of next photon detection. According to the self-adaptive adjustment circuit, by adopting a control method of a current mode, the reverse bias voltage of the SPAD is self-adaptively adjusted, the defect that a traditional voltage mode is complicated to control is overcome, and the self-adaptive adjustment circuit is suitable for array application, easy to expand and capable of achieving consistency detection of the gain of the array single-photon avalanche photodiode.

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...

AI Technical Summary

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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