Magnetic sensor, methods for manufacturing and designing same, and motor device

A method for designing a magnetic sensor including a bridge circuit and a plurality of magnetoresistive elements, wherein

• the bridge circuit includes:
• a first port;
• a second port;
• a third port;
• a fourth port;
• a first resistor section provided between the first port and the second port;
• a second resistor section provided between the second port and the third port;
• a third resistor section provided between the third port and the fourth port;
• and
• a fourth resistor section provided between the fourth port and the first port,
• each of the plurality of magnetoresistive elements includes a magnetization pinned layer having a magnetization whose direction is fixed and a free layer having a magnetization whose direction is variable depending on a magnetic field to be applied,
• the plurality of magnetoresistive elements includes a plurality of first magnetoresistive elements constituting the first resistor section, a plurality of second magnetoresistive elements constituting the second resistor section, a plurality of third magnetoresistive elements constituting the third resistor section, and a plurality of fourth magnetoresistive elements constituting the fourth resistor section,
• the bridge circuit is configured to detect a rotating magnetic field whose direction rotates at a detection position, and
• the method of designing comprising:
• setting directions of magnetizations of a plurality of magnetization pinned layers included in each of the plurality of first magnetoresistive elements, the plurality of second magnetoresistive elements, the plurality of third magnetoresistive elements, and the plurality of fourth magnetoresistive elements so that the bridge circuit generates a first detection signal and a second detection signal each corresponding to a change of the direction of the rotating magnetic field;
• and
• setting the directions of the magnetizations of the plurality of magnetization pinned layers so that a temporal period corresponding to one rotation in the direction of the rotating magnetic field is divided into three or more temporal sub-periods, based on the first detection signal and the second detection signal.