一种星载多光谱TDICCD测试电路设计

The evaluation board design of measurement for Satellite-board multi-spectral TDICCD

摘要:

为了满足星载多光谱TDICCD的测试分析及参数评价,设计了一种多光谱TDICCD的测试电路。该电路由数字电压调节、驱动及信号处理三部分构成,以FPGA为核心,产生多光谱TDICCD工作所需的时序逻辑信号,时序逻辑经驱动电路产生相位正确的脉冲信号驱动CCD工作,CCD将光信号转变成电压信号,电压信号由LM98640进行模数转换成对应的数字量,FPGA将数字量编排成图像数据,通过Camera Link发送给PC机,PC机上位机软件按照国军标《电荷耦合成像器件测试方法》对图像数据进行处理、计算,得出CCD的各个参数指标。测试结果表明,该测试系统具备驱动电压在线实时调节功能,电路噪声为0.24mV,信噪比为56dB,测试重复性误差约为1.44%,满足星载TDICCD参数测试评价需求,已在某型光学卫星用TDICCD研制中得到应用。

Abstract:

In order to meet the analysis and parameter evaluation of multi-spectral TDICCD, a multi-spectral TDICCD measurement circuit was designed. The circuit consists of three parts: digital voltage generator, driver and signal processing. The FPGA generates the logic timing for TDICCD operation. Then the logic timing is used to generate the pulse signals to drive the CCD through the drive circuit. The CCD converts the photos into analog signals. Analog signals are converted to digital numbers by the LM98640. The FPGA arranges the digital numbers into image data and sends it to the PC through Camera Link. The PC host computer software is in accordance with the national military standard "Charge-coupled imaging device test method". Processing and calculating the image data, and obtaining various parameter indexes of the CCD. The test results show that the measurement board can make a convenient voltage-adjustment, and the noise of the measurement board is 0.24mV, the signal-to-noise ratio is 56dB, and the deviation of repeated measurement is about 1.44%, which satisfies the requirements of TDICCD parameter measurement evaluation. The measurement board has been applied to the development of a satellite-board TDICCD.