Luximos: A 768×64 900-fps Tileable Pipelined X-Ray CMOS Image Sensor for Dental Imaging With 2.6 LSB/nGy Sensitivity

In this letter, a stitched array of 768×64 pixels for X-ray dental imaging is presented. The sensor architecture allows to increase the frame rate up to 900 fps thanks to a pipeline approach that minimizes the deadtime between consecutive frames. A column-based ADC converts pixel values in digital form while an external FPGA performs the operation of time-delay integration accumulation, thus increasing the signal-to-noise ratio. Internal programmable gain allows to achieve a maximum sensitivity of 2.6 LSB/nGy and, at the same time, to extend the dynamic range of the sensor in case of high intensity. The final system consists of two sensors each one having a size of 74.5×9 mm, assembled in a PCB and coupled with a high sensitive columnar thallium-doped cesium iodide (CsI(Tl)) scintillator for X-ray conversion. The sensor, fabricated in a standard CMOS 0.15-μm technology with a stitching approach, shows a pixel size of 97 μm.