| 摘要 |
A phase detector (1) includes a crossing-point phase detection circuit (10) to compare signal levels of pairs of sensor signals (U1, V1, W1) and output crossing-point phase detection signals (UV, VW, WU) indicating phases of crossing points between the pairs of the sensor signals, each having a signal level corresponding to a rotational position of a rotor of a motor having coils, a crossing-point level detection circuit (50) to output crossing-point level signals (Y) indicating crossing-point levels detected, a signal selection circuit (20) to select one of the sensor signals as a selection signal, a phase detection circuit (30) to detect that a signal level of the selection signal has reached a threshold level, and output a phase data signal indicating a phase of the rotor corresponding to the threshold level, and a threshold-level correction circuit (60) to correct the threshold level based on the crossing-point level signals (Y). |
