Asahi Kasei Microdevices Corporation

Seiko Nakamoto

Junya Nakanishi

Yutaka Nakanishi

Ryuzo Yamamoto

In a transmission system of an audio signal etc., circuit enlargement is suppressed and deterioration of transmitting signal is reduced. A transmission system including a transmitting apparatus including a first delta-sigma modulator outputting first multi-bit delta-sigma modulated signals of three or more bits and a first code modulator code-modulating first signals of two or more bits located in bit positions higher than a predetermined bit position of the first multi-bit delta-sigma modulated signals based on at least part of a second signal located in one or more bit positions not higher than the predetermined bit position and outputting a plurality of modulated signals; a transmission path transmitting the second signal and the plurality of modulated signals; and a receiving apparatus including a first demodulator demodulating the plurality of the received modulated signals based on at least part of the received second signal is provided.

Transmission system, transmitting apparatus, receiving apparatus, and program

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.

Control method of D/A converter, D/A converter, control method of A/D converter, and A/D converter

An A/D converter comprising: a sampling circuit including a continuous section, a sampling and holding section for intermittently sampling an input signal based on an analog signal input from the continuous section to hold and transfer the sampled signal, and a digital section for outputting a signal transferred from the sampling and holding section as a digital signal; and a control circuit for supplying a clock signal in which jitter is not added to the continuous section and supplying a clock signal in which the jitter is added to the sampling and holding section.

Sampling circuit, A/D converter, D/A converter, and CODEC

A digital-analog converter circuit includes sampling capacitive elements (N) of which one ends are to be electrically connected to and disconnected from input terminals (D, D, DN), to which digital signals are input, via a switch unit (SWu), an operational amplifier (), a switch () capable of electrically connecting and disconnecting the other ends of the sampling capacitive elements (N) and an inverting input terminal of the operational amplifier (), and a switch unit (SWu) that is disposed between nodes between the switch unit (SWu) and the sampling capacitive elements (N) and the output terminal of the operational amplifier () and capable of connecting and disconnecting them. An on-resistance value of a MOS transistor included in the switch () is set to be larger than an on-resistance value of a MOS transistor included in the switch unit (SWu).

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Tokyo, Japan

Seiko Nakamoto