| 摘要 |
PURPOSE:To exercise phase control by a voltage with steady phase error removed through a direct current loop in a steady state and by attaining stable synchronization through an incomplete integration type loop filter in a transient state, by providing the direct-current loop for digital control. CONSTITUTION:The analog phase control circuit is constituted by providing loop filter 1 and voltage control oscillator 2, output voltage Ve of loop filter 1 is applied to adder 4 and LPF5, and direct-current voltage Ve after passing through this LPF5 is converted into a digital value by sample holding circuit 6 and A/D converter 7. The conversion output of the digital value is supplied to D/A converter 9 via processor 8 and a voltage detected by the direct-current loop, converted into an analog value by converter 9, is applied to adder 4. In an initial state, stable synchronization is attained by the loop of incomplete integration type loop filter 1 and adder 4 and in a steady state, phase control is exercised by a voltage with a detected phase error removed by the direct-current loop. |
