Patent ID: 8106647

Claim:
A rotation sensor for detecting rotation of an object, the rotation sensor comprising: a semiconductor substrate; a vertical Hall element formed in the semiconductor substrate to detect a magnetic field parallel to a surface of the semiconductor substrate, the vertical Hall element outputting a detection signal corresponding to the detected magnetic field; a magnetoresistive element formed on the semiconductor substrate and having a resistance value changing with strength of the magnetic field, the magnetoresistive element outputting a resistance signal corresponding to the resistance value, wherein the rotation is detected based on the detection signal and the resistance signal, an arctan calculator; a pulse circuit configured to output a pulse signal by pulsing the detection signal; and a synthesizer, wherein the magnetoresistive element includes a first magnetoresistive element having a first resistance value changing with the rotation of the object and outputting a first resistance signal corresponding to the first resistance value, the magnetoresistive element further including a second magnetoresistive element having a second resistance value changing with the rotation of the object and outputting a second resistance signal corresponding to the second resistance value, the first and second resistance signals having a predetermined phase difference, the arctan calculator outputs an arctan signal by calculating the arctangent of the first and second resistance signals, and the synthesizer outputs a linear signal by synthesizing the arctan signal and the pulse signal, the linear signal representing the rotation of the object over a range of angles from 0° to 360°.