Patent ID: 8773122

Claim:
A hall element control circuit, connected to a hall element via a wiring member, for controlling the hall element, the hall element control circuit comprising: a first terminal for supplying a bias voltage to a high-potential-side input terminal of the hall element; a second terminal final for supplying a ground potential to a low-potential-side input terminal of the hall element; a first transistor whose source terminal is connected to a power supply potential and whose drain terminal is connected to said first terminal; and an operational amplifier for controlling a gate voltage of said first transistor by differentially amplifying a voltage between a predetermined set voltage and a voltage at said first terminal; and a second transistor and a resistor connected in series with each other so as to constitute a current mirror circuit together with a first series circuit where said first transistor and the hall element are connected in series with each other, wherein said operational amplifier uses a connection point voltage between the second transistor and the resistor as a mirror voltage of high-potential-side input terminal voltage of the hall element.