Denso Corporation

Satoshi Ohi

Reiji Iwamoto

A filter circuit includes an input-signal processing section and a signal-level determining section. The input-signal processing section samples and holds a digital input signal input according to a clock signal, outputs the holding signal as a sampling input signal when a level of the digital input signal is constant between sampling points, and reverses the holding signal and outputs the reversed signal as the sampling input signal when the level of the digital input signal changes between the sampling points. The signal-level determining section sequentially delays the sampling input signal from the input-signal processing section into plural stages, outputs a first level signal at a first level when all the delayed signals are at the first level, and outputs a second level signal at a second level when all the delayed signals are at the second level.

Filter circuit for removing noise pulses from digital input signal

A signal processing circuit for a rotation detector outputs accurate rotational information including a rotating direction of a rotor which rotates with an object. A phase difference compensation substantiating block decides whether a predetermined phase difference compensating condition is established. The condition relates to decision whether noise effects on first and second filter signals in first and second filter blocks are different from each other. When the phase difference compensating condition is established, the phase difference compensation substantiating block corrects the phase relationship between first and second phase difference compensation output signals so that the phase relationship is identical to that attained just before the phase difference compensating condition is established.

Growing community of inventors

Osaka, Japan

Satoshi Ohi