| 摘要 |
PURPOSE:To improve the holding characteristic of a phase comparator, by stopping a saw tooth wave generated at the time of the 1st signal at the time of the 2nd signal and holding the saw tooth wave until the next 1st signal, and then, outputting the flat section of the wave and, at the same time, resetting the wave when the 2nd signal is positioned at the second half cycle of the 1st signal. CONSTITUTION:A saw tooth generator which is constituted while including transistors 31, 32, and 34 starts a saw tooth wave upon receiving an input signal 1 by using a reset voltage as an origin and stops the saw tooth wave when another input signal 2 is received. After stopping the saw tooth wave, the generator holds the saw tooth wave until the next signal 1 is inputted and generates another saw tooth wave having a flat section. The flat section is held at a holding circuit 8 after gating a gate circuit 5 by means of the output of a gate pulse generator 4 and the phase compared output of the signals 1 and 2 is fetched through an amplifier 9. When it is discriminated by a discriminating circuit 6 that the signal 2 is positioned at the second half cycle of the signal 1, the output voltage of the circuit 5 is set to a reset voltage by a reset voltage setting circuit 7. Therefore, the holding characteristic of this phase comparator can be improved. |
