| 摘要 |
PROBLEM TO BE SOLVED: To provide an excitation device for exciting a test piece with pulse width modulation (PWM) drive signals that can reduce the effect of noise.SOLUTION: In a gyro sensor, a time to digital converter (TDC) 51 detects the amplitude of a vibrator 11, and a drive circuit 50 (except the TDC 51) determines the duty ratio of PWM drive signals, so that an amplitude has a predetermined size corresponding to the amplitude of the vibrator 11, to output PWM drive signals having the duty ratio. The drive circuit 50 (except the TDC 51) includes: a control circuit 52 that outputs a control value in accordance with the duty ratio of target PWM drive signals; and digitally controlled oscillator (DCO) 53 that performs clocking based on a gate delay time in response to the control value and therefore generates PWM drive signals having a pulse width corresponding to an input control value to output PWM drive signals. |
