Patent ID: 8390282

Claim:
A magnetic sensor circuit, comprising: a Hall element connected to a power supply and a ground by respective first and second pairs of switches; and a magnetic offset cancellation circuit that cancels a magnetic offset of the Hall element, wherein the magnetic offset cancellation circuit comprises: an amplifier circuit; transmission gates comprising NMOS and PMOS transistors coupled to the first and second pairs of switches that switch connections of electrodes of the Hall element and output a voltage of the Hall element to the amplifier circuit; and a drive circuit that drives the transmission gates, the drive circuit comprising: a first MOS transistor and a second MOS transistor connected in series between the power supply voltage and a ground voltage, the first MOS transistor and a second MOS transistor having the same conductivity type; a capacitor in which a first electrode is connected to a node between the first MOS transistor and the second MOS transistor; and an inverter circuit in which an input terminal has a second electrode of the capacitor connected thereto, and wherein the drive circuit includes output terminals connected to the NMOS and PMOS transistors such that the drive circuit, in synchronization with the pairs of switches, supplies voltages higher than a power supply voltage to gates of the NMOS transistors in the transmission gates at a time of turning on the transmission gates.