Single-photon avalanche diode quenching circuit based on offset control differential amplification structure

Abstract

The invention provides a single-photon avalanche diode quenching circuit based on an offset control differential amplification structure. A gate control circuit is used for receiving a gate control enable signal input externally to be in the closed or opened state. A rapid reset circuit is used for receiving a reset signal input externally while the gate control circuit is in the opened state so that the gate control circuit can be in the closed state. When an SPAD detects that a photon generates avalanche current, the avalanche current flows through a detection resistor to generate voltage drop. A low voltage detection circuit adopts the differential amplification structure based on offset control and is used for inducting changes of the input end voltage; when the input end voltage is larger than a detection threshold value of the low voltage detection circuit, output end signals become low-level signals, the detection resistor is controlled to be switched off, and meanwhile a rapid quenching circuit is closed; the rapid quenching circuit is used for accelerating the quenching process when closed, so that the avalanche current is quenched. In the quenching circuit, the detection threshold value of the quenching circuit can be smaller than the turn-on voltage of an NMOS transistor.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, specifically provides a single photon avalanche diode quenching circuit based on an offset control differential amplification structure, and relates to an interface circuit of a single photon avalanche diode array readout circuit in the field of photoelectric detection technology. Background technique [0002] Single-photon detection technology can detect extremely weak light signals, and it is a new detection technology developed in recent years. Single photon detectors are widely used in non-destructive material composition analysis, bioluminescence and radiation detection, detection of astronomical high-energy physical phenomena, laser three-dimensional imaging, deep space or free space communication, and quantum secure communication. With the development of semiconductor photodetector technology, avalanche photodiodes capable of detecting weak signals have reached the level of single p...

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Problems solved by technology

[0005] However, the inventors have found through research that the common problem of the above structure is that the detection threshold is relatively high, and the detection threshold of the detection circuit must be greater than the turn-on voltage of the NMOS tube, which will cause the quenching circuit to be less affected by the nonlinear effect of the SPAD bias voltage. Big

However, the detection threshold of the traditional quenching circuit is limited by the turn-on voltage of the MOS tube, which cannot achieve low threshold detection.

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