| 主权项 |
1. A signal amplifier for a phase detector generating a phase information signal, based on plural sensor signals having amplitude levels in accordance with a rotational position of a rotor of a motor having a plural-phase coil to detect the rotational position thereof, comprising:
a first phase detector configured to compare the plural sensor signals with specified plural threshold levels to detect a phase and produce a first phase information signal representing the phase; a phase counter configured to count the number of the phase to determine a signal amplification section of each of the sensor signals, based on the first phase information signal; an amplitude detector configured to detect or estimate a peak level of the sensor signal to produce a result signal; a signal amplification factor operation circuit configured to operate a signal amplification factor of each of the sensor signals such that the peak level or the estimated peak level of the senor signal represented by the result signal from the amplitude detector has a specified amplitude level; a signal amplification factor controller configured to determine the signal amplification section of each of the sensor signals, based on the number of the phase, and store and produce the signal amplification factor in accordance with the signal amplification section; and a signal amplification unit configured to amplify an amplitude level of each of the sensor signals, based on the signal amplification factor. |
