| 摘要 |
PURPOSE:To achieve skew adjustment with high accuracy, by assembling a voltage controlled delay circuit used as a delay element in a phase locked loop circuit. CONSTITUTION:Points of skew adjustment are taken as points A and B. A voltage controlled delay circuit VCD is used as a delay element. A phase locked loop circuit consists of the VCD1, a phase comparator 2, a charge pump circuit 3, a low pass filter 4, a DC amplifier 5 and a logical gate circuit 8. When the phase of the point B leads than that of the point A, the delay time of the VCD is increased by an output voltage of a DC amplifier 5. When the phases of two inputs of the phase comparator 2 are equal, the output voltage of the DC amplifier 5 is constant. Thus, the skew at the points A and B can be corrected. |
