Abstract: To provide a rotation angle sensor which outputs N periods (N>1) of a first signal of a first phase and a second signal of a second phase forming a predetermined phase angle with the first phase per single rotation of a rotating body. The rotation angle sensor includes a calibration parameter calculating part which calculates, in a mechanical angle of one angular range having a first mechanical angle different from a reference mechanical angle as its starting point, based on the first signal and the second signal, a calibration parameter which calibrates an error in a moving radius of the rotating body in the reference mechanical angle of the rotating body. The one angular range may have the first mechanical angle as its starting point and a second mechanical angle as its ending point.

Abstract: Provided is a calibration apparatus including: an acquisition unit for acquiring a detection position of a mobile body for each actual position of the mobile body; a calculation unit for calculating, for a detection position of each actual position of the mobile body, an error between a slit position signal for detecting a slit position and an ideal slit number corresponding to the actual position; a determination unit for determining whether two or more actual positions having at least partially different slit numbers in units of first slits of a predefined number correspond to a same detection position; and a generation unit for generating, in response to the two or more actual positions corresponding to a same detection position, a correction value for correcting an error by a magnitude between errors at the two or more actual positions with respect to the slit position signal at the detection position.

Abstract: A delta-sigma modulator and a delta-sigma converter include an analog amplifying unit to amplify an analog signal and having at least a primary feedback coefficient, a quantizer to quantize an output signal of the analog amplifying unit, a DA converter to perform DA conversion on output of the quantizer and output a feedback signal, an adder-subtractor to input into the analog amplifying unit an analog signal obtained by subtracting the feedback signal from an analog signal input therein, a reset circuit to reset the analog amplifying unit at predetermined periods, and a control circuit to control the analog amplifying unit so that the analog amplifying unit operates as an integrator with the primary feedback coefficient of 1 until a predetermined period elapses after the reset circuit resets the analog amplifying unit and as an amplifier with the primary feedback coefficient of greater than one after the predetermined period has elapsed.

Abstract: A delta-sigma modulator and a delta-sigma converter include an analog amplifying unit to amplify an analog signal and having at least a primary feedback coefficient, a quantizer to quantize an output signal of the analog amplifying unit, a DA converter to perform DA conversion on output of the quantizer and output a feedback signal, an adder-subtractor to input into the analog amplifying unit an analog signal obtained by subtracting the feedback signal from an analog signal input therein, a reset circuit to reset the analog amplifying unit at predetermined periods, and a control circuit to control the analog amplifying unit so that the analog amplifying unit operates as an integrator with the primary feedback coefficient of 1 until a predetermined period elapses after the reset circuit resets the analog amplifying unit and as an amplifier with the primary feedback coefficient of greater than one after the predetermined period has elapsed.

Abstract: An A/D converter includes an incremental delta-sigma A/D modulator and a digital operation unit to which a signal from the A/D modulator is input. The A/D modulator includes an analog integrator configured to integrate input signals, a quantizer configured to quantize output signals of the analog integrator, a D/A converter configured to D/A convert an output of the quantizer, and a reset signal output device configured to reset the analog integrator and the digital operation unit. The analog integrator includes plural switched capacitors and a first analog integrator connected to the switched capacitors. The first analog integrator includes an operational amplifier connected to the switched capacitors and a feedback capacitor each connecting an input and an output of the operational amplifier.

Abstract: An A/D converter includes an incremental delta-sigma A/D modulator and a digital operation unit to which a signal from the A/D modulator is input. The A/D modulator includes an analog integrator configured to integrate input signals, a quantizer configured to quantize output signals of the analog integrator, a D/A converter configured to D/A convert an output of the quantizer, and a reset signal output device configured to reset the analog integrator and the digital operation unit. The analog integrator includes plural switched capacitors and a first analog integrator connected to the switched capacitors. The first analog integrator includes an operational amplifier connected to the switched capacitors and a feedback capacitor each connecting an input and an output of the operational amplifier.