应用于辐照实验的通用CCD测试电路设计

电荷耦合器件(CCD)辐射效应测试系统需具备通用性。通常情况下需要为每一种CCD设计一款测试电路,无法满足通用性要求,通用性电路的难点在于不同CCD要求不同的驱动通道数、驱动时序、信号占空比及工作点。提出了一种适用于多种CCD的测试电路设计方法。以现场可编程门阵列(FPGA)负责时序发生、工作点调节及整个系统的控制,驱动模块采用工作点可调的模式,并结合电荷泵技术,仅需更改FPGA设计及给驱动模块提供不同的工作点电压,便可使以上驱动参数可调,实现测试电路的通用性。采用该方法进行测试还可以适应CCD辐照后工作点的变化。最后通过正确驱动TCD1209线阵CCD和4096×96型TDI-CCD,并对TDI-CCD总剂量辐照实验进行正确的参数测试,验证了通用测试电路设计方法的可行性。

Design of Universal Testing Circuit for CCD Applied in Irradiation Test

Irradiation-testing system of CCD has to be universal.One testing circuit for one kind of CCD with traditional method could not meet the requirements.The difficulty of universal testing circuit was that different kinds of CCD require different number of channels,driving time-sequence,duty cycle and operating point.Here,one design method which can be applied to many kinds of CCD was proposed.Generating of the pulse time sequence,adjusting of the operating point and controlling of the whole system were completed by FPGA.Operating point was adjustable based on the technique of charge-pumping in driving unit.Hence,all parameters mentioned were adjustable by redesigning FPGA and changing voltage for driving unit and the universal testing circuit was realized.It can also test the variation of operating point of CCD after irradiation.Finally,the realization of this method was validated by successfully drivering TCD1209 CCD and 4096×96 TDI-CCD and achiving correct testing result after irradiation.