Phase-coupled clock signal generator and character generator comprising such a phase-coupled clock signal generator

摘要

A phase-coupled clock signal generator comprises a start-stop oscillator (1) to which a control signal is applied. The clock frequency is dependent on an adjusting value (F). For adjusting and monitoring the clock frequency, the clock signal generator is provided with a counter (2). This counter counts the number of received clock pulses during a predetermined period and generates a corresponding counting value (C). A control circuit (3) compares the counting value (C) with a reference value and adapts the adjusting value (F). Such a clock signal generator is suitable for On Screen Display applications in a television receiver.