一种用于PAL_D制解码电路的调试方法

A Method of Adjusting the PALD Decoding Circuit

本文从分析PAL_D解码电路存在幅度和相位失真条件出发,在理论上对测试信号的选择进行了探讨,提出用隔行色度信号测量和调整解码电路矢量图的方法,利用该方法可直接从解码电路输出端获得对延时分离级幅度和相位误差参量的调整和测量,从而提高了调试速度和精度。

This paper discusses the selection among the different test signals in a PALD decoding circuit theorefically, and then presents a method of measuring and adjusting vector diagrams in a decoding circuit by using interlacing line chrominance signal. The method can be used to obtain, directly form the output terminals of decoding circuit, the measurement and adjustment of the amplitude and phase error in the delay time—seperation unit, and therefore, improve the speed and accuracy of the adiustment efficiently.