基于CPLD工作模式可调的线阵CCD驱动电路设计

Design of Linear CCD Driving Circuit with Flexible Working Modes Based on the CPLD

针对传统驱动电路一旦做出修改,则需对硬件或程序进行改变的缺点,以型号为TCD1707D的线阵CCD为例,介绍了一种工作模式可调的驱动方法.该方法是利用复杂可编程逻辑器件和控制外端结合,通过分别设置内外触发来实现的.在外触发模式下,利用外触发脉冲,可由用户控制CCD的曝光和信号输出时间;内触发时,可以调节CCD的积分时间和驱动频率.为提高信号输出质量,针对EMC问题给出了线阵CCD的外围驱动电路.实验结果表明,该方法调试方便、电路结构简单、集成度较高、输出信号可靠稳定、受干扰小,可配合多种用户需要,对高速精确测量及线阵推扫模式具有一定参考价值.

A driving circuit design of TCD1707D was presented.It could overcome the shortcoming of common circuit which is needed to change the hardware or programme in case the condition has been modified.This design shows two flexible working modes,one is internal burst mode,the other is external burst mode.In the external burst mode,the users can control the time of exposure and signal outputs by means of external triggered pulse.Integration time and driving frequency of CCD can be tuned simultaneously in the other mode.The function is carried out by setting internal and external triggered respectively with complex programmable logic device （CPLD） and an external control.CPLD is combined with the control circuit,so external commands can produce corresponding control signals to drive curcuit nomally.And then through the pins of CPLD,the output signals can be transfered to the CCD chip.In addition,in order to solve the EMC problem,the article presents a linear CCD periphery circuit,which is improved the quality of CCD signal outputs.This method has the advantages of convenient debugging,simple circuit and high integration level.It is proved by experiments that the system outputs basically match the simulation,and the signal outputs are more reliable,more stable and less interferential than common system.And the system could fulfill a wide range of users’ needs,especially can be used for accurate high-speed measurement and push-broom.