A system includes an analog-to-digital converter configured to convert an analog signal generated by a digital sensor into a digital signal, and a testing apparatus configured to be enabled after the analog-to-digital converter operates in a testing mode, wherein the testing apparatus comprises a filter configured to receive the digital signal from the analog-to-digital converter, and apply a filtering process to the digital signal, a control circuit configured to terminate the filtering process after an output of the control circuit reaches a predetermined reference value, and a result register configured to receive a result generated by the filter after the control circuit terminates the filtering process.

The present technology relates to a signal processing apparatus, a signal processing method, and a program that make it possible to cope with an output of a PCM signal using one DSD signal. A distribution apparatus includes an extraction section that, in a case where a PCM signal having a predetermined sampling frequency is generated from a DSD signal, extracts a predetermined number of samples from the DSD signal around samples at a predetermined interval determined by the predetermined sampling frequency, and a filtering section that generates the PCM signal having the predetermined sampling frequency by filtering the extracted predetermined number of samples. The present technology is applicable to, for example, a distribution apparatus, etc., that distributes the PCM signal to a client apparatus.

The present technology relates to a signal processing apparatus, a signal processing method, and a program that make it possible to cope with an output of a PCM signal using one DSD signal. A distribution apparatus includes an extraction section that, in a case where a PCM signal having a predetermined sampling frequency is generated from a DSD signal, extracts a predetermined number of samples from the DSD signal around samples at a predetermined interval determined by the predetermined sampling frequency, and a filtering section that generates the PCM signal having the predetermined sampling frequency by filtering the extracted predetermined number of samples. The present technology is applicable to, for example, a distribution apparatus, etc., that distributes the PCM signal to a client apparatus.

This disclosure provides an active envelope detector to generate an output voltage based on an input radio-frequency (RF) signal. The active envelope detector includes a plurality of transistors configured to operate in a sub-threshold mode and generate an output voltage based on the input RF signal. A delta-modulation analog-to-digital converter (ADC) and a sigma-delta modulation ADC are provided. Both ADCs include an implementation of the active envelope detector to receive input RF signals.

The present technology relates to a signal processing apparatus, a signal processing method, and a program that permit switching between a plurality of DSD signals having different sampling frequencies using a simple configuration. An acquisition section acquires a digital audio signal having a given sampling frequency selected from among the plurality of digital audio signals acquired by delta-sigma modulating an audio signal at a plurality of sampling frequencies. An interpolation section subjects the acquired digital audio signal to a pre-interpolation process when the sampling frequency of the acquired digital audio signal is lower than an operating clock of a delta-sigma demodulator. The present technology is applicable, for example, to a signal processing apparatus.

The present technology relates to a signal processing apparatus, a signal processing method, and a program that permit switching between a plurality of DSD signals having different sampling frequencies using a simple configuration. An acquisition section acquires a digital audio signal having a given sampling frequency selected from among the plurality of digital audio signals acquired by delta-sigma modulating an audio signal at a plurality of sampling frequencies. An interpolation section subjects the acquired digital audio signal to a pre-interpolation process when the sampling frequency of the acquired digital audio signal is lower than an operating clock of a delta-sigma demodulator. The present technology is applicable, for example, to a signal processing apparatus.

An audio amplifier system includes a delta-sigma modulator configured to receive an m-bit digital audio input signal and to generate a pulse density modulated signal based on the m-bit digital audio input signal. An analog power stage is coupled to the delta-sigma modulator to receive the pulse density modulated signal and amplify the pulse density modulated signal to generate an amplified pulse density modulated signal. A feedback circuit is coupled to the delta-sigma modulator and the analog power stage. The feedback circuit is configured to receive the amplified pulse density modulated signal and the pulse density modulated signal and to determine a digital error signal representative of a difference between the amplified pulse density modulated signal and the pulse density modulated signal. The feedback circuit is further configured to provide the digital error signal to the delta-sigma modulator for applying the digital error signal to a representation of the m-bit digital audio input signal.

An audio amplifier system includes a delta-sigma modulator configured to receive an m-bit digital audio input signal and to generate a pulse density modulated signal based on the m-bit digital audio input signal. An analog power stage is coupled to the delta-sigma modulator to receive the pulse density modulated signal and amplify the pulse density modulated signal to generate an amplified pulse density modulated signal. A feedback circuit is coupled to the delta-sigma modulator and the analog power stage. The feedback circuit is configured to receive the amplified pulse density modulated signal and the pulse density modulated signal and to determine a digital error signal representative of a difference between the amplified pulse density modulated signal and the pulse density modulated signal. The feedback circuit is further configured to provide the digital error signal to the delta-sigma modulator for applying the digital error signal to a representation of the m-bit digital audio input signal.

A hybrid delta modulator that can be used as a variable threshold neuron in a neural network is described. The hybrid delta modulator exhibits a memory of the prior state of the modulator, similar to a delta modulator, and receives a sum-of-products signal from a weighting circuit and generates a quantized output stream that represents the sum-of-products signal, potentially including an activation function and offset. With appropriately selected components, the hybrid delta modulator separates the integral function of the feedback from the gain function. Further, the gain can be selected, and the characteristic of the output pattern can be tailored to include an arbitrary combination of the input and the rate of change of the input. The use of a hybrid delta modulator of the present approach provides a simpler solution and better performance than many prior art neurons.

A hybrid delta modulator that can be used as a variable threshold neuron in a neural network is described. The hybrid delta modulator exhibits a memory of the prior state of the modulator, similar to a delta modulator, and receives a sum-of-products signal from a weighting circuit and generates a quantized output stream that represents the sum-of-products signal, potentially including an activation function and offset. With appropriately selected components, the hybrid delta modulator separates the integral function of the feedback from the gain function. Further, the gain can be selected, and the characteristic of the output pattern can be tailored to include an arbitrary combination of the input and the rate of change of the input. The use of a hybrid delta modulator of the present approach provides a simpler solution and better performance than many prior art neurons.