Abstract: A data receiving apparatus is provided to receive command data encoded by using a combination of high-level periods during which there is radio wave and low-level periods during which there is no radio wave. The data receiving apparatus is provided with a receiving circuit including a differential amplifier circuit receiving the command data through an antenna, and a demodulator outputting a reproduced signal corresponding to the command data in response to an output of the differential amplifier; and an offset adjustment switch circuit judging a logic level of the reproduced signal in the low level periods of the command data while the receiving circuit receives the command data, and generates offset switch signals based on the logic level of the reproduced signal in the low level periods. The differential amplifier circuit includes an offset control section adjusting an offset value of the differential amplifier circuit in response to the offset switch signals.

Abstract: A variation detection device has a processor, an AD converter converting a signal voltage output from a sensor to generate an AD converted value and outputting the AD converted value to the processor, a temperature sensor detecting a temperature of the sensor, and a memory storing a table which indicates a relationship between temperatures and initial values. When receiving the AD converted value, the processor identifies a temperature of the sensor based on an output of the temperature sensor, reads out an initial value corresponding to the identified temperature from the table, and calculates a variation between the initial value and the AD converted value.

Abstract: A data receiving apparatus is provided to receive command data encoded by using a combination of high-level periods during which there is radio wave and low-level periods during which there is no radio wave. The data receiving apparatus is provided with a receiving circuit including a differential amplifier circuit receiving the command data through an antenna, and a demodulator outputting a reproduced signal corresponding to the command data in response to an output of the differential amplifier; and an offset adjustment switch circuit judging a logic level of the reproduced signal in the low level periods of the command data while the receiving circuit receives the command data, and generates offset switch signals based on the logic level of the reproduced signal in the low level periods. The differential amplifier circuit includes an offset control section adjusting an offset value of the differential amplifier circuit in response to the offset switch signals.

Abstract: A data communication device includes a receiving circuit configured to receive a data signal in an active state. An intermittent activation control circuit activates the receiving circuit into the active state in a predetermined time interval. A control unit operates in response to the data signal received by the receiving circuit. Also, the control unit controls the time interval of the intermittent activation control circuit.

Abstract: A semiconductor apparatus includes an amplifying unit, a bias controlling unit, an AD converting unit and a controlling unit. The amplifying unit is configured to amplify an input signal to output an amplified signal. The bias controlling unit is configured to generate a bias voltage to be applied to the input signal. The AD converting unit is configured to AD-convert the amplified signal into an output signal. The controlling unit is configured to output a control signal to the bias controlling unit. The controlling unit outputs the control signal when an output value indicated by the output signal is equal to a predetermined value. The bias controlling unit changes the bias voltage in response to the control signal.

Abstract: A semiconductor integrated circuit has: a differential amplifier circuit including a first MOS transistor connected between a first node and a common node and a second MOS transistor connected between a second node and the common node; a first current supply circuit configured to supply current to the first node; and a second current supply circuit configured to supply current to the second node. A current supply ability of the first current supply circuit is variable.

Abstract: A semiconductor device includes a reference voltage generating section configured to generate a first reference voltage and a second reference voltage based on a voltage supplied from an external power supply, and an AD (analog/digital) conversion circuit operating based on the first reference voltage to generate an AD conversion signal corresponding to an output signal supplied from an external device. The second reference voltage is supplied to the external device, and a ratio of the first reference voltage and the second reference voltage is kept to a constant value regardless of a temperature of the semiconductor device.

Abstract: A semiconductor device includes a reference voltage generating section configured to generate a first reference voltage and a second reference voltage based on a voltage supplied from an external power supply; and an AD (analog/digital) conversion circuit operating based on the first reference voltage to generate an AD conversion signal corresponding to an output signal supplied from an external device through AD conversion. The second reference voltage is supplied to the external device, and a ratio of the first reference voltage and the second reference voltage is kept to a constant value regardless of a temperature of the semiconductor device.

Abstract: A variation detection device has a processor, an AD converter converting a signal voltage output from a sensor to generate an AD converted value and outputting the AD converted value to the processor, a temperature sensor detecting a temperature of the sensor, and a memory storing a table which indicates a relationship between temperatures and initial values. When receiving the AD converted value, the processor identifies a temperature of the sensor based on an output of the temperature sensor, reads out an initial value corresponding to the identified temperature from the table, and calculates a variation between the initial value and the AD converted value.

Abstract: A semiconductor apparatus includes an amplifying unit, a bias controlling unit, an AD converting unit and a controlling unit. The amplifying unit is configured to amplify an input signal to output an amplified signal. The bias controlling unit is configured to generate a bias voltage to be applied to the input signal. The AD converting unit is configured to AD-convert the amplified signal into an output signal. The controlling unit is configured to output a control signal to the bias controlling unit. The controlling unit outputs the control signal when an output value indicated by the output signal is equal to a predetermined value. The bias controlling unit changes the bias voltage in response to the control signal.

Abstract: A data communication system includes a plurality of sensor initiators, each of which has first and second antennas; a communication control module and a plurality of sensor communication modules. The communication control module is connected with the plurality of sensor initiators through a LAN and is configured to control the plurality of sensor initiators such that a first electromagnetic wave signal for a command data signal is transmitted through the first antennas. Each of the plurality of sensor communication modules includes at least a sensor and third and fourth antennas.

Abstract: A semiconductor integrated circuit has: a differential amplifier circuit including a first MOS transistor connected between a first node and a common node and a second MOS transistor connected between a second node and the common node; a first current supply circuit configured to supply current to the first node; and a second current supply circuit configured to supply current to the second node. A current supply ability of the first current supply circuit is variable.

Abstract: A data communication device includes a receiving circuit configured to receive a data signal in an active state. An intermittent activation control circuit activates the receiving circuit into the active state in a predetermined time interval. A control unit operates in response to the data signal received by the receiving circuit. Also, the control unit controls the time interval of the intermittent activation control circuit.

Abstract: A ring oscillation circuit comprises a ring oscillator in which a plurality of inverters are connected in a ring and in which a constant current is supplied to each of the inverters, and a constant-current circuit which generates the constant current, wherein a value of the constant current is determined based on a threshold voltages of the inverters.

Abstract: A semiconductor integrated circuit device, which is driven using Vd1 supplied to external power supply terminal 3 and which includes internal circuit 10 with desired functions, such as a CPU, comprises step-up circuit 13, which steps up Vd1 at a predetermined step-up ratio k and outputs Vd2 (=k×Vd1); and voltage detecting circuit 15, which is driven using Vd2 as a power supply and which compares a predetermined Vref1 to Vd3 (=a×Vd2) given by dividing Vd2 with dividing ratio a and outputs the resultant Vcp1. In addition, the semiconductor integrated circuit device with the voltage detecting circuit that can detect the power supply voltage accurately and surely even if the power supply voltage provided externally falls to 1 V or lower, comprises oscillation circuit 19 and level shift circuit 17, which is driven using Vd1 as a power supply and which changes the Vcp1 level and outputs Vcp2.

Abstract: A semiconductor integrated circuit device, which is driven using Vd1 supplied to external power supply terminal 3 and which includes internal circuit 10 with desired functions, such as a CPU, comprises step-up circuit 13, which steps up Vd1 at a predetermined step-up ratio k and outputs Vd2 (=k×Vd1); and voltage detecting circuit 15, which is driven using Vd2 as a power supply and which compares a predetermined Vref1 to Vd3 (=a×Vd2) given by dividing Vd2 with dividing ratio a and outputs the resultant Vcp1. In addition, the semiconductor integrated circuit device with the voltage detecting circuit that can detect the power supply voltage accurately and surely even if the power supply voltage provided externally falls to 1 V or lower, comprises oscillation circuit 19 and level shift circuit 17, which is driven using Vd1 as a power supply and which changes the Vcp1 level and outputs Vcp2.