Asahi Kasei Microdevices Corporation

Ryuzo Yamamoto

Junya Nakanishi

Daisuke Matsuoka

Seiko Nakamoto

Tatsuya Chubachi

Provided is a DA converter for outputting an analog signal according to an input digital signal, including a plurality of current output units to be input with the digital signal, which output a current according to the digital signal to a corresponding wiring, a conversion unit provided with a plurality of feedback paths respectively coupled to wirings corresponding to the current output units, and which selects at least one wiring among the wirings corresponding to the current output units and output an analog signal according to a current flowing in the selected wiring, and a first noise reduction unit provided with a plurality of first switches each of which switches whether to electrically connect to at least one wiring among the wirings corresponding to the current output units, and reduces a noise component generated in at least one of the plurality of current output units from the electrically coupled wiring.

DA converter

To reduce distortion of output analog signals generated at a current-output DA converter. A DA converter that outputs a differential analog signal corresponding to an input digital signal is provided, including: a current output unit outputting a current corresponding to the digital signal to each of first and second wires; a converting unit outputting, as positive-side and negative-side analog signals, voltage signals based on currents flowing through the first and second wires, respectively; a first noise reducing unit having: a first switch switched to be or not to be electrically connected with the first wire; and a first buffer provided between the first switch and a reference potential; and a second noise reducing unit having: a second switch switched to be or not to be electrically connected with the second wire; and a second buffer provided between the second switch and the reference potential.

DA converter and DA conversion method

A DA converter to reduce second-order harmonic distortion more precisely with convenient configurations. A DA converter including: a DA converting unit to input reference voltage and a digital value and output an analog signal according to the digital value based on the reference voltage; and a superimposing unit to superimpose, on the reference voltage, a superimposing signal based on the analog signal that is output from the DA converting unit, and a DA converting method are provided. The DA converter may further include a setting input unit to input setting regarding at least one of a superimposing amount and a sign of an analog signal to be included in the superimposing signal. Also, an adjusting apparatus and an adjusting method to adjust the DA converter are provided.

DA converter, DA converting method, adjusting apparatus, and adjusting method

The present invention relates to a control method of a D/A converter, a D/A converter, a control method of an A/D converter, and an A/D converter that can suppress an existing n-th harmonic without using a large-scale circuit, such as a bootstrap. A D/A converter () of the present invention is a D/A converter () that can suppress the generation of an existing n-th harmonic (n is an integer of 2 or more) of an analog output signal. The D/A converter () includes a D/A conversion unit () that converts an input digital signal into an analog signal and a control unit () that arbitrarily controls the timing of the sampling phase and the integral phase of the D/A conversion unit (). The D/A conversion unit () is configured to generate an arbitrary n-th harmonic and superimpose the arbitrary n-th harmonic on an analog output signal including the existing n-th harmonic.

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Tokyo, Japan

Ryuzo Yamamoto