以c8051F020为核心的CCD驱动与采集系统的设计

Development of driving and sampling circuit for CCD based on c8051F020

介绍了以单片机为核心设计CCD驱动系统的新方法。该方法采用新型高集成度(集成AD及RAM)、超高速(单周期指令50 ns)单片机c8051F020为微处理器,在根本上克服了传统单片机CCD驱动系统中驱动频率慢的弱点;驱动脉冲由单片机的通用输入输出口产生,各路驱动脉冲间的时序关系由软件控制,免除外围电路中使用单稳态触发器;采用该方法的驱动电路只需使用2颗芯片(单片机与CCD),电路连接简单且板面积大为减小。该驱动系统在采用单片机片内集成的500 kHz模数转换器时工作频率接近500 kHz,积分时间由单片机内部的定时器作为标准时钟源确定,精度可以达到50 ns。

A new method to design driving circuit for CCD based on microprocessor is introduced.A kind of newly high integration(on-chip AD and RAM) and high speed(single cycle direction(50 ns)) c8051F020 is employed as the microprocessor.The drawback of low driving frequency by using conventional microprocessor is overcome.The pulses for driving CCD are generated by the microprocessor's general input-output port controlled by software to determine the timing relationship between pulses without the monostabillity trigger.The driving circuit based on this new method needs only two simply connected chips on the electric board with small size.The driving frequency is about(500 kHz) when the 500 kHz on-chip ADC is used.The integration time of CCD is determined by the timer inside the CPU,which makes the timing accuracy about 50 ns.