| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic sensor circuit capable of obtaining a precise detection result, by compensating for changes or suppressing variations in properties of a Hall element and its peripheral circuits. SOLUTION: A monitor circuit 7b is made up so that a resistor Rm1 having a property identical to that of the Hall element is disposed therein, and a control transistor Q2 is connected to the resistor Rm1 in series, and respective components of the resistor Rm1, the control transistor Q2 and an error amplifier AMP1 are connected so as to configure a constant current circuit. An amplifier which is used as an amplifier 4b connected to the Hall element 3, has a Gilbert cell and first/second current sources IR1, IR2 connected so as to configure a Gm amplifier. A monitor signal from the monitor circuit 7b is applied to a circuit position of the Gilbert cell to which current is supplied from the second current source IR2, thereby varying the amplification factor (gain) of the amplifier 4b and compensating for a changed portion contained in a voltage signal caused by the change in the property of the Hall element. COPYRIGHT: (C)2006,JPO&NCIPI
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