| 摘要 |
PROBLEM TO BE SOLVED: To enhance the accuracy of a hysteresis operation by forming digitally a circuit in hysteresis operation in waveforming and shaping. SOLUTION: A comparator 21 compares an input voltage Va and a threshold voltage Vc to apply waveform shaping to a sensor signal. A period measurement circuit 4 measures a period of an output signal of the comparator 21 and a step waveform voltage generating circuit 5 generates a step waveform voltage based on the measured period and a V-I conversion circuit 6 converts the step waveform voltage into a current and the circuit 6 supplies a current to a resistor 23d or 23e via analog switches 22a, 22b closed/open in response to the operation of the comparator 21, thus, the stepwise offset voltage is added to the input voltage Va or the threshold voltage Vc for the hysteresis operation. |
