Design of 128×32 GM-APD array ROIC with multi-echo detection for single photon 3D LiDAR

Single photon flash light detection and ranging (LiDAR), which is based on Geiger Mode avalanche photodiode (GMAPD) array, enables superior sensitivity and detection range to obtaining depth information. The Flash LiDAR captures an entire 3D image by single laser pulse, much faster than conventional LiDAR based on the scanning of a single detector over the scene. In conventional advanced driver assistant systems (ADAS), closer and weaker reflections caused by the environmental factors will cause misidentification. Furthermore, power dissipation and limited pixel size are enormous challenges for Readout Integrated Circuit (ROIC) design. The paper proposes the design of ROIC with Multi-Echo Detection for 128×32 GM-APD Array. The pixel includes active quenching and reset circuit of GM-APD, and embedded 11-bit Time to Digital Converter (TDC) offers precise distance resolution by Time of Flight (TOF) measurement. The proposed ROIC is designed with 0.18μm CMOS process. Due to shared DFFs by TDC and shift register, 90μm pixel pitch is realized with Multi-Echo Detection function. Global clock gating(GCG) and shift clock gating(SCG) techniques bring the power dissipation down to 464.6mW.