An Event-Driven Motion Perception ROIC for Cryogenic Infrared Focal Plane Arrays

This article presents an event-driven, high-speed readout integrated circuit (ROIC) with in-sensor trace detection capabilities for cryogenic infrared focal plane arrays (FPAs), aimed at the next-generation smart infrared motion perception applications. To achieve high accuracy and agile motion recognition with low power consumption and bandwidth requirements, we propose an event-driven image and trace detection method. The proposed pixel consists of two key components: 1) event detection (ED) and 2) imaging and trace detection (ITD). In response to the demands of cryogenic infrared FPAs, we introduce a synchronized linear response ED circuit that encodes temporal variations in infrared radiation into 1.5-bit events. Additionally, we propose an in-sensor trace generation method that fuses spatial and temporal information streams, enabling high-accuracy motion recognition while reducing computational and power requirements. When coupled with a postprocessor, the event-driven mechanism reduces the need for extensive motion localization and imaging efforts in motion analysis. Meanwhile, the trace information generated by the ITD module further enhances motion recognition accuracy for identified objects of interest. The ROIC provides a spatiotemporal redundancy compression and an energy-efficient solution for infrared motion perception applications. A prototype based on a $16\times 16$ array with a 20- $\mu $ m pixel pitch, fabricated using a 0.18- $\mu $ m 1P5M CMOS process, demonstrates event-driven motion perception, consuming 11.93 mW ( $40.75~\mu $ W for the array and 10.95 mW for the output buffers) at a 12.2-kHz event and image frame frequency. Detailed test and measurement results of the prototype are provided.