锁相技术在雷达、通信、电视和其他自动控制系统中早已得到广泛应用。六十年代中,国外在磁记录电路中引用锁相技术,推动了高密度磁记录技术的发展。近年国内磁盘、磁带的研制也纷纷采用锁相技术,取得一定成果。本文讨论在磁盘改进调频制(MFM制)读写方式中采用数字式锁相技术的自同步电路。本系统框图如图1所示。 Phase locking technology has long been widely used in radar, communications, television and other automatic control systems. In the 1960s, foreign countries in the magnetic recording circuit reference phase-locked technology, and promote the development of high-density magnetic recording technology. In recent years, the domestic disk, tape development also have phase-locked technology, and achieved some results. This article discusses the self-synchronization circuit using digital phase-locked technology in the disk read / write system for improved frequency modulation (MFM). The system block diagram shown in Figure 1.