Fish & Richardson P.C.
Clock delay compensating and duty controlling apparatus of a phase-locked loop
 For clock delay compensation and duty control of a phase-locked loop in a decoder of a video signal receiving system, phases of two input clocks received into a phase comparative detector are compared to divide a reference clock from an oscillator of the phase comparative detector for obtaining a resultant phase error output in a divider in accordance with the result of the phase comparison, a duty ratio of the output clock therefrom is controlled in a duty controller to allow the phase comparative detector to be utilized free from the duty ratio of the clock, and a clock delay compensator performs correction of clock delay compensation of the system operated at high speed in the synchronized phase-locked loop, thereby controlling a duty ratio of a signal divided in the divider when determining accuracy, frequency and stabilization in the duty controller, and correcting an error in delay time by adding the clock delay compensator. 
Hyundai Electronics Industries Co., Ltd.
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H03K H03L H03K
inventional inventional inventional
Seung Y.
Lee