| 摘要 |
PURPOSE:To prevent a shift of a resonating state of a vibrator including a first terminal to which a driving voltage is supplied and a second terminal whose phase is shifted by a specific number from a phase of a signal of the first terminal at the resonating state, by generating a signal of a frequency multiplied by a specific number of times based on the signal impressed to the first terminal. CONSTITUTION:A 90 deg. phase circuit, 40 is constituted of a phase comparator 41, a loop filter 42, a VCO 43, a frequency divider 44 and flip-flops 45 and 46. The comparator 41, the filter 42, the VCO 43 and the frequency divider 44 constitute a multiplier circuit 40. An output signal from the VCO 43 has its frequency divided to 1/4 by the frequency divider 44 and is fed back to the comparator 41. Therefore, the VCO 43 outputs a signal of a frequency four times a frequency (f) of a signal input to the circuit 40. The signal is impressed as a clock pulse to the flip-flops 45, 46, so that a signal S42 having a phase one cycle delayed to that of a signal S43 and a cycle four times that of the signal S43 is obtained at arm output terminal of the flip-flop. In other words, the signal S42 of the circuit 40 has the same frequency as a signal S41 and the phase 90 deg. delayed to the signal S41. |
