设计了一款用于激光雷达的CMOS单光子飞行时间图像传感器.该传感器集成了16个结构优化的单光子雪崩二极管像素和一个双计数器结构的13-bit时间数字转换器电路.每个像素单元包括一个新型的主动淬灭-恢复电路.该设计通过优化器件的保护环来降低器件的暗噪声; 带有反馈回路的主动淬灭-恢复电路用于降低死时间; 时间数字转换器采用双计数器结构来避免计数器的亚稳态导致的计数错误.基于CMOS 180 nm标准工艺制作了该传感器.测试结果表明：在1 V的过偏压下, 单光子雪崩二极管列阵的中值暗计数率为8 kHz; 在550 nm波长光照下探测效率最高, 为18%; 设计的主动淬灭-恢复电路将死时间有效降低至8 ns; 时间数字转换器的分辨率为416 ps, 帮助整个系统实现厘米级距离分辨率.该传感器在0.5 m距离下实现了空间分辨率为320×160的深度图像, 其测距的最大非线性误差为1.9%, 准确度为3.8%.

A CMOS single photon avalanche diode based time-of-flight sensor is presented for light detection and ranging applications. The sensor integrates 16 structure-optimized single photon avalanche diode pixels and a dual-counter-based 13-bit time-to-digital converter. Each pixel unit has a novel active quench and recharge circuit. The dark noise of single photon avalanche diode is reduced by optimizing the guard ring of the device. The active quench and recharge circuit with a feedback loop is proposed to reduce the dead time. A dual-counter-based time-to-digital converter is designed to prevent counting errors caused by the metastability of the counter in the time-to-digital converter. The sensor is fabricated in 180 nm CMOS standard technology. The measurement results show the median dark count rate of the single photon avalanche diode is 8 kHz at 1 V excess voltage, the highest photon detection efficiency is 18 % at 550 nm light wavelength. The novel active quench circuit effectively reduces the dead time down to 8 ns. The time-to-digital converter with 416 ps resolution makes the system achieve the centimeter-accuracy detection. A 320×160 depth image is captured at a distance of 0.5 m. The maximum depth measurement nonlinear error is 1.9% and the worst-case precision is 3.8%.