Design and implementation of timing generator of frame transfer area-array CCD camera

摘要

Frame transfer area-array CCD camera is the perfect solution for high-end real-time medical, scientific and industrial applications because it has characteristics of high fill factor, low dark current, high resolving power, high sensitivity, high linear dynamic range and electronic shutter capability. Time sequences of frame transfer area-array CCD camera have two compact segments: CCD driving sequences and CCD signal processing sequences. Proper working of CCD sensor lies on good driving sequences while accurate CCD signal processing sequences ensures high quality of CCD image. The relationship among CCD camera time sequences is complex and precise. The conventional methods are uneasy to implement time sequences of Frame transfer area-array CCD. Embedded designing method is introduced in this paper and field programmable gate array device is chosen as the hardware design platform. Phase-locked loops are used for precise phase shifting and embedded logic analyzer for waveform verification. CCD driving clocks, electronic shutter signal, A/D and black pixels clamp clocks and double correlation sampling clocks have been attained on the hardware platform and this timing generator can control exposure time flexibly. High quality images have been acquired through using this timing generator on the CCD circuit system board which has been designed by our team.