128 × 128 Pixel CMOS Event Camera With Multi-Bit Temporal Difference Event Generation

This paper presents 128 × 128 pixel CMOS event camera front-end and its ADC that can produce multi-bit temporal difference events from subsequent pixel intensity values. The implementation was done with 180 nm CMOS technology. The designs of the pixel front-end, column ADC, FPN compensation, as well as their simulation and measurement results, are presented. Our implementation uses temporal events to construct a grayscale frame without the need to a full range ADC. This approach provides a means to have pixel grayscale values that are in sync with temporal difference events, wherein having access to both grayscale information and temporal difference events could be useful in further processing steps that are needed in applications such as moving object detection and classification.