Abstract: A semiconductor device includes first and second terminals, a reference resister being coupled between the first and second terminals, third and fourth terminals, a sensor resister being coupled between the third and fourth terminals, a first buffer which supplies a first reference voltage to the first terminal, a second buffer which supplies a second reference voltage to the fourth terminal, a reference voltage generation circuit which supplies one of first and second voltages alternately in a time division manner as the first reference voltage and supplies the other as the second reference voltage, a first analog-to-digital conversion circuit which performs analog-to-digital conversion on a signal line coupled to the third terminal, an RC filter disposed on the signal line, a noise detector which detects noise of the signal line, wherein a time constant of the RC filter is changed based on a result of the noise detector.

Abstract: A semiconductor device includes an analog-digital conversion circuit that converts a voltage at a node between a reference resistor and a sensor resistor into output data, the reference resistor and the sensor resistor being connected in series. The semiconductor device calculates a resistance value of the sensor resistor using a first output data obtained in a first conversion phase and second output data obtained in a second conversion phase. In the first conversion phase, a high potential side voltage is applied to one end of the reference resistor and a low potential side voltage is applied to one end of the sensor resistor. In the second conversion phase, the low potential side voltage is applied to one end of the reference resistor and the high potential side voltage is applied to one end of the sensor resistor.

Abstract: A semiconductor device includes first and second terminals, a reference resister being coupled between the first and second terminals, third and fourth terminals, a sensor resister being coupled between the third and fourth terminals, a first buffer which supplies a first reference voltage to the first terminal, a second buffer which supplies a second reference voltage to the fourth terminal, a reference voltage generation circuit which supplies one of first and second voltages alternately in a time division manner as the first reference voltage and supplies the other as the second reference voltage, a first analog-to-digital conversion circuit which performs analog-to-digital conversion on a signal line coupled to the third terminal, an RC filter disposed on the signal line, a noise detector which detects noise of the signal line, wherein a time constant of the RC filter is changed based on a result of the noise detector.

Abstract: A semiconductor device includes an analog-digital conversion circuit that converts a voltage at a node between a reference resistor and a sensor resistor into output data, the reference resistor and the sensor resistor being connected in series. The semiconductor device calculates a resistance value of the sensor resistor using a first output data obtained in a first conversion phase and second output data obtained in a second conversion phase. In the first conversion phase, a high potential side voltage is applied to one end of the reference resistor and a low potential side voltage is applied to one end of the sensor resistor. In the second conversion phase, the low potential side voltage is applied to one end of the reference resistor and the high potential side voltage is applied to one end of the sensor resistor.

Abstract: An electronic navigation calculator having first input key group for navigation functions, second input key group for navigation numerals, third input key group for navigation operations, a memory device supplied with information signals from said first, second and third input key groups and memorizing said supplied information signals, operational and control device for carrying out predetermined navigation calculations in accordance with information signals from said input key groups, and output device for indicating the calculated results. As a result, a calculation of direction, speed, position and time of a moving body is carried out in accordance with said information signals from said first, second and third input key groups and the calculation result is displayed.