Imec, the Belgian nanoelectronics research centre, will present a prototype of a time-delay-integration (TDI) image sensor developed for the French Space Agency, CNES, at this week's CMOS Image Sensors for High Performance Applications workshop in Toulouse.
The image sensor is based on their embedded charge-coupled device (CCD) in CMOS technology. CNES plans to use the technology for space-based earth observation.
The prototype image sensor combines a light-sensitive, CCD-based TDI pixel array with peripheral CMOS readout electronics. A TDI imager is a linear device that synchronises the linear motion of the scene with multiple samplings of the same image, thereby increasing the signal-to-noise ratio. By combining the TDI pixel array with CMOS readout circuitry on the same die, the Imec scientists have produced a camera-on-a-chip or system-on-a-chip (SOC) imager, which reduces the overall system complexity and cost.
The prototypes were fabricated using a 130nm process with an additional CCD process module. A charge transfer efficiency of 99.9987 per cent has been measured ensuring almost lossless transport of charges in the TDI array.
