| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor control device and a motor control circuit which are capable of detecting the speed of rotation of a rotor more accurately than before. <P>SOLUTION: An FG signal is generated in an FG coil 31 with the integral rotation of the rotor 12 and an FG magnet 123. The FG signal is inputted to a differential amplifier 32 in a state that an in-phase noise signal is mixed therein. Since input impedance on the input terminal 321 side and input impedance on the input terminal 322 side are matched with each other on the occasion, a level difference between the in-phase noise signal at the input terminal 321 and that at the input terminal 322 is not produced nearly at all. In the differential amplifier 32, accordingly, the inputted FG signal is differentially amplified, while the in-phase noise signal is canceled and removed. Accordingly, a hysteresis comparator 33 can binarize the differentially amplified FG signal so as to generate a pulse signal, without being affected by the in-phase noise signal. <P>COPYRIGHT: (C)2009,JPO&INPIT |
