| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-sensitivity and high-precision magnetic field search device which is made small. SOLUTION: This is a magnetic field search device which uses an MI element varying in impedance with an external magnetic field. An amorphous magnetic material 10 is used for the MI element. An oscillator 13 supplies a pulse current to the MI element and a signal processing circuit 100 detects the voltage across the MI element. Namely, the impedance corresponding to the external magnetic field is detected from the voltage. At this time, this device is equipped with an amplifier 120 whose amplification factor is adjustable, a control circuit 130 which controls the amplification factor, and a memory device 140 which stores a controlled variable. When this device is manufactured, a numeral is inputted from an adjustment input terminal 145 to adjust the amplification factor. Namely, variance in the sensitivity of the MI element is eliminated when the device is manufactured. The device except the MI element is composed of an integrated circuit and the MI element and integrated circuit are molded in one body to constitute a molded IC chip. Consequently, the high-sensitivity and high-precision magnetic field search device which is made small is provided.
|
