HORIZONTAL SYNCHRONIZATION FOR DIGITAL TELEVISION RECEIVER

摘要

A horizontal synchronizing system, comprising: a source of a horizontal synchronizing signal (1fH INPUT); a source (20, 28) of first and second higher frequency horizontal drive signals; a phase detector (14) for generating a first control voltage (17) responsive to the horizontal synchronizing signal and the first horizontal drive signal; a source (22, 24) of a second control signal (25); and, a switch (18) for selectively supplying the first control signal to the source of the drive signals for a phase-locked mode of operation at the first higher frequency and supplying the second control signal to the source of the drive signals for a phase-unlocked mode of operation at the second higher frequency.