A Dual Active Quenching Circuit With Temperature Compensation Technique for Breakdown Voltage Shift of Single-Photon Avalanche Diodes

A front-end circuit of single-photon avalanche diode (SPAD) which achieves dual active quenching and compensates the breakdown voltage shift due to temperature is presented in this article. A well-defined quenching circuit reduces noise signals such as dark count rate (DCR) and afterpulsing probability and enhances resolutions when applied to imaging applications. Meanwhile, it requires a compact design to optimize light absorption. In addition, the inherent breakdown-voltage of SPAD is vulnerable to its temperature variation, leading to a significant performance degradation. The proposed circuit achieves dual active quenching by a common-source (CS) amplifier, controlling anode and cathode at the same time. Moreover, it mitigates the breakdown-voltage shift by exploiting the characteristic that MOSFET current and resistance decrease as temperature increases, maintaining a constant excess bias voltage for SPAD. Simulation results demonstrate that the quenching time has decreased by 45% compared to conventional approaches. Measurement results indicate a twofold reduction in breakdown-voltage shift with temperature variation, along with a 30% reduction in DCR and a 40% reduction in afterpulsing probability. The designed circuits were fabricated using $0.18~\mu $ m complementary metal-oxide-semiconductor (CMOS) technology.