在盖革模式下工作的雪崩光子二极管( APD)也称为单光子雪崩光子二极管( single photon avalanche photon diode, SPAD)是一种常用于激光测距成像领域的单光子探测器。本文针对 SPAD探测应用中的淬火问题, 设计了一种电容淬火( capacitive quenching circuit, CQC)电路。首先, 根据 SPAD器件的性能参数, 建立了 SPAD的 SPICE等效模型, 并通过无源淬火电路验证了该模型。其次, 基于该等效模型的基础上, 仿真验证了所设计的 CQC淬火电路的淬火效果。仿真结果表明：所设计的 CQC电路不仅具有门控有源淬火电路的优点, 而且具有更稳定的偏置电压和击穿电流。本文设计的 CQC淬火电路的淬火时间和恢复时间分别为 16 ns和 41 ns, 基本可满足单光子测距的应用需求。

An avalanche photon diode(APD) operating in Geiger mode, also called a single photon avalanche photon diode(SPAD), is a single photon detector commonly used in the field of imaging with laser ranging. In this paper, a capacitive quenching circuit(CQC) is designed to solve the quenching problem in SPAD detection applications. First, according to the performance parameters of SPAD devices, a SPICE equivalent model of SPAD is established and verified by passive quenching circuit. Second, based on the SPICE equivalent electrical model, the quenching effect of the designed CQC is simulated. The simulation results show that the designed CQC not only has the advantages of a gated active quenching circuit but also has a more stable bias voltage and breakdown current. The quenching time and recovery time of the CQC are 16 ns and 41 ns, respectively, which essentially meet the requirements for the application of single photon measurement.