MAGNETIC FIELD ANGLE MEASUREMENT DEVICE AND ROTATION ANGLE MEASUREMENT APPARATUS USING SAME

摘要

Provided are a magnetic field angle detection device and a rotation angle detection apparatus which use a TMR element, wherein even when the MR ratio of the TMR element increases, the accuracy of the measured angle is not lowered. Specifically provided is a magnetic field angle measurement device comprising a magnetic sensor comprising a TMR element having a pinned layer, and a magnetic field angle detection circuit. The magnetic field angle detection circuit comprises a power supply unit for outputting constant voltage as bias voltage to the TMR element of the magnetic sensor, and a current detection unit for detecting the output current of the TMR element. The TMR element current is measured while the terminal voltage of the TMR element is kept constant with the input impedance of the current detection unit set to zero, thereby improving the accuracies of angles measured by the magnetic field detection device and the rotation angle detection apparatus.