Patent ID: 9281936
Filing Date: 2016-03-08
CPC Classification: G01D,H02P,H04L

Claim Text:
1. A phase detector, comprising: a crossing-point phase detection circuit to compare signal levels of respective pairs of multiple sensor signals and output crossing-point phase detection signals indicating phases of crossing points between the respective pairs of the sensor signals, each of the sensor signals having a signal level corresponding to a rotational position of a rotor of a motor having multiple coils; a crossing-point level detection circuit to detect crossing-point levels indicating signal levels of the crossing points between the respective pairs of the sensor signals and output multiple crossing-point level signals indicating the crossing-point levels detected; a signal selection circuit to select one of the sensor signals as a selection signal; a phase detection circuit 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 which the signal level has reached; and a threshold-level correction circuit to correct the threshold level based on the multiple crossing-point level signals.