Abstract: Before a temperature characteristic of a band gap reference circuit is tested, temperature dependencies of a reference voltage and an absolute temperature proportional voltage for a plurality of samples are measured. When the temperature characteristic is tested, based on a difference ?Vref between the reference voltage of the band gap reference circuit at a predetermined temperature and a median value of the reference voltages of the plurality of samples, a difference ?Vptat between the absolute temperature proportional voltage of the band gap reference circuit at a predetermined temperature and a median value of the absolute temperature proportional voltages of the plurality of samples is calculated.

Abstract: It is possible to detect a failure in a temperature sensor while preventing enlarging of a circuit scale. A temperature measurement circuit 10 includes temperature sensors 20 and 30, and a comparator 40. The temperature sensor 20 includes a temperature detection unit 21 including a resistive element, a resistance value of which varies in accordance with temperature changes, and an AD converter which converts a voltage of the temperature detection unit 21 into a temperature digital value D1. The temperature sensor 30 includes a ring oscillator 31 which oscillates at a cycle that is temperature dependent, and generates a digital value D2 based on an oscillating signal output by the ring oscillator 31. The comparator 40 compares the temperature digital values D1 and D2, and outputs a signal indicating whether the temperature sensor 20 is normal or not based on a comparison result.

Abstract: It is possible to detect a failure in a temperature sensor while preventing enlarging of a circuit scale. A temperature measurement circuit 10 includes temperature sensors 20 and 30, and a comparator 40. The temperature sensor 20 includes a temperature detection unit 21 including a resistive element, a resistance value of which varies in accordance with temperature changes, and an AD converter which converts a voltage of the temperature detection unit 21 into a temperature digital value D1. The temperature sensor 30 includes a ring oscillator 31 which oscillates at a cycle that is temperature dependent, and generates a digital value D2 based on an oscillating signal output by the ring oscillator 31. The comparator 40 compares the temperature digital values D1 and D2, and outputs a signal indicating whether the temperature sensor 20 is normal or not based on a comparison result.

Abstract: An analog-digital converter according to the present invention includes an input polarity switching unit, an integrator that integrates an input signal, an integrator output adjusting circuit that adjusts an output voltage of the integrator, a window comparator, and a controller that controls the input polarity switching unit, the integrator output adjusting circuit, and the window comparator, and generates a digital signal. When the output voltage of the integrator reaches a first reference voltage, the controller resets reference voltage of a high-voltage side comparator to a second reference voltage. Further, when the output voltage of the integrator reaches a third reference voltage, the controller resets reference voltage of a low-voltage side comparator to a fourth reference voltage. According to the analog-digital converter of the present invention, it is possible to prevent device breakdown and occurrence of through current due to fluctuation of the output voltage of the integrator.

Abstract: There is provided an analog-to-digital converter capable of performing analog-to-digital conversion with good accuracy. The analog-to-digital converter in accordance with the present invention includes a dither generation circuit 11 which generates dither; an input polarity switching unit 1 which switches a polarity of an input signal; an integrator 2; an integrator output regulator circuit 5 which regulates an output voltage of the integrator 2; a window comparator 3; a control circuit 4 which uses the comparison result of the window comparator 3 to control the input polarity switching unit 1, the integrator output regulator circuit 5, and the window comparator 3 as well as to generate a digital signal. The dither generation circuit 11 generates dither in such a manner that a cycle in which the digital signal is read is an integral multiple of a dither cycle.

Abstract: There is provided an analog-to-digital converter capable of performing analog-to-digital conversion with good accuracy. The analog-to-digital converter in accordance with the present invention includes a dither generation circuit 11 which generates dither; an input polarity switching unit 1 which switches a polarity of an input signal; an integrator 2; an integrator output regulator circuit 5 which regulates an output voltage of the integrator 2; a window comparator 3; a control circuit 4 which uses the comparison result of the window comparator 3 to control the input polarity switching unit 1, the integrator output regulator circuit 5, and the window comparator 3 as well as to generate a digital signal. The dither generation circuit 11 generates dither in such a manner that a cycle in which the digital signal is read is an integral multiple of a dither cycle.

Abstract: An analog-digital converter according to the present invention includes an input polarity switching unit, an integrator that integrates an input signal, an integrator output adjusting circuit that adjusts an output voltage of the integrator, a window comparator, and a controller that controls the input polarity switching unit, the integrator output adjusting circuit, and the window comparator, and generates a digital signal. When the output voltage of the integrator reaches a first reference voltage, the controller resets reference voltage of a high-voltage side comparator to a second reference voltage. Further, when the output voltage of the integrator reaches a third reference voltage, the controller resets reference voltage of a low-voltage side comparator to a fourth reference voltage. According to the analog-digital converter of the present invention, it is possible to prevent device breakdown and occurrence of through current due to fluctuation of the output voltage of the integrator.

Abstract: According to one aspect of the present invention, there is provided a dither circuit including a dither generating circuit generating a plurality of complementary signal pairs, and a dither input circuit generating a plurality of dither signals from the plurality of complementary signal pairs to add the generated dither signals to an analog input signal, in which the plurality of complementary signal pairs have different frequencies with each other, the dither input circuit includes capacitors provided for each of the plurality of complementary signal pairs and a plurality of switch pairs including first and second switches having one terminals connected to each one terminal of the capacitors, and the other terminals of the capacitors are connected to an adding point to the analog input signal, the first switch supplies ones of the complementary signal pairs to one terminals of the capacitors when a clock signal is in effective state, and the second switch supplies the others of the complementary signal pairs

Abstract: A semiconductor circuit apparatus includes a booster which is connected to a single power supply and outputs a power supply voltage of the power supply or a voltage different from the power supply voltage, and a boost controller which controls whether to output the power supply voltage of the power supply or the voltage different from the power supply voltage.

Abstract: According to one aspect of the present invention, there is provided a dither circuit including a dither generating circuit generating a plurality of complementary signal pairs, and a dither input circuit generating a plurality of dither signals from the plurality of complementary signal pairs to add the generated dither signals to an analog input signal, in which the plurality of complementary signal pairs have different frequencies with each other, the dither input circuit includes capacitors provided for each of the plurality of complementary signal pairs and a plurality of switch pairs including first and second switches having one terminals connected to each one terminal of the capacitors, and the other terminals of the capacitors are connected to an adding point to the analog input signal, the first switch supplies ones of the complementary signal pairs to one terminals of the capacitors when a clock signal is in effective state, and the second switch supplies the others of the complementary signal pairs

Abstract: A semiconductor circuit apparatus includes a booster which is connected to a single power supply and outputs a power supply voltage of the power supply or a voltage different from the power supply voltage, and a boost controller which controls whether to output the power supply voltage of the power supply or the voltage different from the power supply voltage.