Design of a Fast CMOS APS Imager for High Speed Laser Detections

In this paper, the results of the first temporal resolution imager CMOS for high-speed laser pulse characterisation are presented. This new imager can replace the conventional streak camera using a charge-coupled device (CCD) sensor for some applications. It produces the intensity information in function of time and one spatial dimension (Iph = f (x, t)). The time information is obtained for the prototype to delay successively the integration phase in each pixel of the same row. The different noise sources for an APS sensor such as the shot noise due to the photo sensor, the flicker noise and the thermal noise due to the transistors are studied to determine the fundamental limits on image sensor. The prototype imager named FAMOSI (FAst MOS Imager) consists of an array of 64 x 64 active pixel sensors that are integrated in AMS 0.6 μm CMOS technology. Each pixel size is 13 μm × 13 μm and has a fill factor of 28%. At 50 frames/s, theoretical and experimental results show a total noise of 95± 4 electrons, a fixed pattern noise of 2% (saturation voltage is 760 mV), a dynamic range of 64 dB and a power consumption of 25 mW. The conversion gain is 6.73 ± 0.25 μV/electrons and the time resolution is 0.8 ns.