Sensor device with bias voltage correction to compensate for change in characteristics of bridge circuit
AssigneeMurata Manufacturing Co., Ltd.
InventorYasuhide Takase
Life of this patent
Estimating the term…
Abstract
In a sensor device, a bias circuit includes a bias voltage generation circuit, a regulator circuit, an impedance calculation circuit, and a bias voltage correction circuit. The bias voltage generation circuit generates a bias voltage required to operate the bridge circuit. The regulator circuit applies the bias voltage to the bridge circuit and monitors a bias current supplied to the bridge circuit. The impedance calculation circuit receives a value of the bias voltage and a value of the bias current and calculates an impedance of the bridge circuit. Based on the impedance, the bias voltage correction circuit causes the bias voltage to be corrected to a voltage that compensates for a change in characteristics of the bridge circuit.
Claims15
A sensor device comprising:
- a bridge circuit including at least one sensor, characteristics of which change in accordance with a detected physical quantity;
- a detection signal reception circuit to receive a sensor detection signal that is output from a detection signal output end of the bridge circuit in accordance with a change in characteristics of the sensor;
- a bias voltage generation circuit to generate a bias voltage required for an operation of the bridge circuit;
- a regulator circuit to apply the bias voltage generated by the bias voltage generation circuit to a bias end of the bridge circuit and monitor bias current supplied to the bridge circuit;
- an impedance calculation circuit to receive a value of the bias voltage generated by the bias voltage generation circuit and a value of the bias current monitored by the regulator circuit and calculate an impedance of the bridge circuit;
- and
- a bias voltage correction circuit to cause, based on the impedance of the bridge circuit calculated by the impedance calculation circuit, the bias voltage generated by the bias voltage generation circuit to be corrected to a voltage that compensates for the change in characteristics of the bridge circuit.
Dependencies are inferred from the claim text.