Time-amplitude conversion circuit with high dynamic range and measurement method thereof

Abstract

The invention discloses a time-amplitude conversion circuit with a high dynamic range, and belongs to the technical field of single photon detection. The time-amplitude conversion circuit comprises anintegral timing module and a row selection read-out module, the input end of the integral timing module is separately connected with the output ends of an integral signal generation logic unit and afeedback control logic unit, and the output end of the integral timing module is respectively connected with the input ends of the feedback control logic unit and the row selection read-out module. The invention further discloses a measuring method of the time-amplitude conversion circuit. The simulated timing detection scheme for photon flight time is used, a folding integral method is adopted,and then the charge of the positive plate of the integral capacitor is monitored; the small layout area, low power consumption and pixel fill factors of the circuit are ensured; and the voltage swingdynamic range is effectively improved, the time resolution and the measurement precision are improved, the clock feed-through effect at the switch node is reduced, the electric leakage phenomenon after the switch is turned off is effectively relieved, the holding time is prolonged, the manufacturing cost is reduced, the performance consistency between circuits is good, and the rate of finished products is high.

Description

technical field [0001] The invention belongs to the technical field of single photon detection, and in particular relates to a high dynamic range time-amplitude conversion circuit and a measurement method thereof. Background technique [0002] Single-photon avalanche photodiode (Single-Photon Avalanche Diode, SPAD) has significant advantages such as high avalanche gain, fast single-photon response speed, high detection sensitivity, low manufacturing cost and low power consumption, and can obtain time and space information of photon signals. It has shown broad application prospects in laser ranging, bioluminescent lifetime imaging and 3D imaging. [0003] At present, the single-photon imaging chip based on time correlation mainly adopts the time-to-digital conversion (Time-to-Digital Convert, TDC) photon time-of-flight measurement method, although the TDC circuit has a high time resolution and a strong ability to suppress noise and Anti-interference ability, but its structur...

AI Technical Summary

Problems solved by technology

[0006] However, the integrated voltage of the existing TAC circuit is limited by the power supply voltage, the voltage swing range is small, the voltage cannot be quantified with high precision, and there are problems such as short full-scale time and low time resolution. Therefore, it is very necessary to propose a new type of TAC circuit. TAC circuit structure

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