大面阵InGaAs基线性APD单片激光雷达读出电路

ROIC of ladar based on large array InGaAs linear APD

摘要: 基于大面阵InGaAs基线性背照工作模式APD光敏芯片，采用SMIC 0.35 μm 3.3 V CMOS工艺实现了一款单片集成面阵激光雷达读出电路。电路芯片与APD光敏芯片的每个像元通过In柱互连，实现电流脉冲的有效传输与接收。仿真和测试表明，基于可调节共源共栅输入级和自偏置共源放大级的像元级前置放大器实现了等效5 μA@2.5 ns脉宽的电流检测灵敏度；在片上125 MHz主时钟下，基于计数型和压控延迟型的二段式像元级TDC，通过多相位时钟插值技术实现了1 ns的高精度时间分辨率；采用分时供电的工作模式，32×32面阵读出电路芯片功耗节省了65%。

Abstract: A large array ROIC was designed by SMIC 0.35 μm 3.3 V CMOS technology for large array InGaAs linear APD which worked on back-illuminated mode. Each pixel of the ROIC and APD was interconnected by indium bump, realizing the effective transmission and reception of current pulse. Simulation and test shows that the equivalent current sensitivity of the pixel preamplifier is 5 μA@2.5 ns pulse width by using cascade input stage and self-biased common source amplifier stage. Based on counting TDC and voltage-controlled delay TDC union structure and at 125 MHz master clock on chip, the accuracy of the pixel TDC which uses multiple clock phase interpolating is 1 ns. The power consumption of 32×32 ROIC is reduced by 65% by using time sharing power supply technology.