Horizontal synchronization for digital television receiver

摘要

A horizontal synchronizing system, comprising: a source of a horizontal synchronizing signal; a source of first and second higher frequency horizontal drive signals; a phase detector for generating a first control voltage responsive to the horizontal synchronizing signal and the first horizontal drive signal; a source of a second control signal; and, a switch 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.