高速CCD成像电路抗串扰技术

为了解决高速CCD成像电路串扰问题,分析了产生串扰的原因,建立了CCD成像电路的串扰模型,提出了有效的抗串扰技术。对多通道的CCD视频信号采用带状线而非微带线并使用防护布线进行隔离。对多通道的电源供电进行了隔离,设计并采取有效的去耦电容布线方法,降低了寄生电感,避免了由电源公共阻抗引起的串扰。采用统一的地平面,对模拟电路和数字电路进行分区布局,避免了地弹对信号的影响。针对一个串扰较严重的CCD成像电路进行了实验,结果表明：采取上述抗串扰技术后,通道隔离度大于60 dB,有效降低了串扰,提高了图像质量。

Anti-crosstalk techniques for high-speed CCD imaging circuit

In order to overcome the crosstalk of a high speed CCD imaging circuit,the reasons of the crosstalk are analyzed and the crosstalk models of CCD imaging circuit are established.The striplines instead of microstrips are used for the multi-channel CCD video signals and the guard lines are used for the striplines to isolate further.To reduce the crosstalk caused by the common impedance of a power supply,the isolated multi-channel power supplies are designed and the effective routing method for decoupling capacitors is used to lower parasitic inductances.The analog and digital parts are layout separately and a whole ground plane is used to reduce the ground bounce.Experiments for a CCD imaging circuit with much severe crosstalk problems are performed by these techniques,results show that the channel isolation is large than 60 dB.The crosstalk is reduced efficiently and the image quality is improved.