Seiko Epson Corporation

Fumihito Baisho

Takao Katayama

Tsutomu Nonaka

Akihiro Fukuzawa

Akinari Todoroki

Burton Alexander

Provided is a semiconductor device including: a pulse-width modulation circuit configured to pulse-width modulate a signal based on a first pulse-code modulated signal that is a sound source signal, and output a first pulse-width modulated signal; a first conversion circuit configured to convert a second pulse-width modulated signal based on the first pulse-width modulated signal into a second pulse-code modulated signal; and a comparison circuit configured to convert the first pulse-code modulated signal into a first comparison target signal by an inversely convertible conversion method, convert the second pulse-code modulated signal into a second comparison target signal by the conversion method, and compare the first comparison target signal with the second comparison target signal.

Semiconductor device and electronic apparatus

Provided is a semiconductor device including: a first modulation circuit configured to receive a first sound source signal, sigma-delta modulate a signal based on the first sound source signal, and output a first sigma-delta modulated signal; a second modulation circuit configured to pulse-width modulate a signal based on the first sigma-delta modulated signal, and output a first pulse-width modulated signal; a first modulation inspection circuit configured to inspect the first modulation circuit; and a second modulation inspection circuit configured to inspect the second modulation circuit, in which the first modulation inspection circuit and the second modulation inspection circuit are separated from each other.

An audio mixing device includes a gain setting circuit configured to set first to n-th gains based on a command input from the outside, n being an integer of two or more, and a mixing circuit configured to output a mixing signal obtained by mixing two or more of first to n-th multiplication data obtained by respectively multiplying first to n-th audio data by the first to n-th gains. In a case where the j-th gain of the first to n-th gains is set to a first value, when the j-th gain is to be set to a second value different from the first value, the gain setting circuit transitions the j-th gain from the first value to the second value in a stepwise manner in a j-th gain change section of first to n-th gain change sections.

Audio mixing device and electronic device

An audio mixing device includes: a gain setting circuit configured to set first to n-th gains based on a command input from the outside, n being an integer of 2 or more; and a mixing circuit configured to output a mixing signal obtained by mixing two or more of first to n-th multiplication data obtained by respectively multiplying first to n-th audio data by the first to n-th gains.

A circuit device () includes a PWM signal output circuit () that outputs a PWM signal (SPWM) to a sound outputter (), and a processing circuit () that controls the PWM signal output circuit (). The frequency band that the sound outputter () can output is denoted as an outputtable band, and the frequency band lower than a lower limit of the outputtable band is denoted as a non-output low frequency band. The PWM signal output circuit () outputs a PWM signal (SPWM) based on pseudo sound data in which overtones, of a plurality of overtones of a fundamental tone belonging to the non-output low frequency band, that belong to the outputtable band are used.

Circuit device, sound reproduction device, and electronic apparatus

To decrease the number of arithmetical operations in a filtering process for decoding a digital signal and reduce a cost required for decoding. A filtering method for use in decoding a digital signal from a frequency domain to a time domain includes: a first step of multiplying an input data stream and a transformation matrix that is decomposed into a sparse matrix from an inverse MDCT transformation matrix for making the inverse MDCT transformation of the input data stream composed of a plurality of data blocks, and has a smaller size than the inverse MDCT transformation matrix, to acquire an output data stream composed of a plurality of data blocks; a second step of storing predetermined data contained in each data block of the output data stream; and a third step of generating the digital signal in the time domain on the basis of each data block acquired at the first step and the predetermined data stored at the second step in processing the former stage data block.

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Tachikawa, Japan

Fumihito Baisho