An interface circuit for a bridge sensor has a switch that connects to a resistive bridge circuit. The resistive bridge circuit includes a first input terminal, a second input terminal, and a pair of resistive branches that connect between the first and second input terminals. Both of the resistive branches include an output terminal. The switch is connected to the first input terminal and is in series with both resistive branches for connecting and disconnecting a voltage source from the resistive branch output terminals.

An interface circuit for a bridge sensor has a switch that connects to a resistive bridge circuit. The resistive bridge circuit includes a first input terminal, a second input terminal, and a pair of resistive branches that connect between the first and second input terminals. Both of the resistive branches include an output terminal. The switch is connected to the first input terminal and is in series with both resistive branches for connecting and disconnecting a voltage source from the resistive branch output terminals.

Disclosed is a sensor with compensation circuit for compensating offset by use of a switching circuit. The sensor has two operation modes for generating two output voltages, respectively. Offset is compensated by adding the two output voltages, and magnitude of the offset is calculated by subtracting the two output voltages. A noise threshold is set for checking if the circuit is affected by interference. When the circuit is affected by interference, the adding result of the two output voltages will be larger than the noise threshold, the output data will be hold and not updated, then a reminding signal will be issued to show that the circuit is affected by interference, and the output data flickers on a display unit when the adding result of the two output voltages is larger than the noise threshold for showing the circuit is affected by interference.

Disclosed is a sensor with compensation circuit for compensating offset by use of a switching circuit. The sensor has two operation modes for generating two output voltages, respectively. Offset is compensated by adding the two output voltages, and magnitude of the offset is calculated by subtracting the two output voltages. A noise threshold is set for checking if the circuit is affected by interference. When the circuit is affected by interference, the adding result of the two output voltages will be larger than the noise threshold, the output data will be hold and not updated, then a reminding signal will be issued to show that the circuit is affected by interference, and the output data flickers on a display unit when the adding result of the two output voltages is larger than the noise threshold for showing the circuit is affected by interference.

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.

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.

Disclosed is a sensor with compensation circuit for compensating offset by use of a switching circuit. The sensor has two operation modes for generating two output voltages, respectively. Offset is compensated by adding the two output voltages, and magnitude of the offset is calculated by subtracting the two output voltages. A noise threshold is set for checking if the circuit is affected by interference. When the circuit is affected by interference, the adding result of the two output voltages will be larger than the noise threshold, the output data will be hold and not updated, then a reminding signal will be issued to show that the circuit is affected by interference, and the output data flickers on a display unit when the adding result of the two output voltages is larger than the noise threshold for showing the circuit is affected by interference.

Disclosed is a sensor with compensation circuit for compensating offset by use of a switching circuit. The sensor has two operation modes for generating two output voltages, respectively. Offset is compensated by adding the two output voltages, and magnitude of the offset is calculated by subtracting the two output voltages. A noise threshold is set for checking if the circuit is affected by interference. When the circuit is affected by interference, the adding result of the two output voltages will be larger than the noise threshold, the output data will be hold and not updated, then a reminding signal will be issued to show that the circuit is affected by interference, and the output data flickers on a display unit when the adding result of the two output voltages is larger than the noise threshold for showing the circuit is affected by interference.

A sensor device includes a bridge circuit, a bias circuit, and a detection signal receiving circuit. The bridge circuit includes four sensor elements connected in a bridge. The bias circuit includes an oscillation circuit and an averaging circuit. The oscillation circuit outputs an oscillation signal, in which an output voltage in a first output state and an output voltage in a second output state with temperature dependency repeat alternately at a predetermined ratio. The averaging circuit averages the output voltage of the oscillation circuit and applies the averaged output voltage as a bias voltage to a bias end of the bridge circuit. By applying this voltage, the bias circuit excites the bridge circuit and compensates for a temperature characteristic of the sensitivity by offsetting a temperature fluctuation due to a temperature change in its sensitivity.

A semiconductor substrate includes a first portion and a second portion. The first portion of the substrate has a first deformation-stress sensor capable of supplying a first stress signal. The second portion of the substrate has a second deformation-stress sensor capable of supplying a second stress signal. The first stress signal and second stress signal are processed by a circuit to produce a compensation signal. The compensation signal is applied in feedback to one of the first and second stress signals to compensate for variations induced in said one of the first and second stress signals by stresses in the semiconductor substrate.