摘要:
Systems and methods are provided for converting input data streams having variable input sample rates to an output sample rate, which systems and methods are used in processing the data streams. In one embodiment, a system includes a clock source, a counter configured to count cycles for a corresponding data stream, and a data processor. The data processor is configured to read the number of cycles counted by the counter between received frame sync signals and to convert the first data stream to the predetermined output sample rate based on the corresponding number of cycles counted.
摘要:
Systems and methods for performance improvements in digital switching amplifiers using low-pass filtering to reduce noise and distortion. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low-pass filter configured to filter audio signals output by the plant. The filtered output of the plant is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC.
摘要:
Systems and methods for performance improvements in digital switching amplifiers using a low delay corrector. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low delay corrector configured to receive signals output by the plant. The output of the low delay corrector is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC.
摘要:
A low delay corrector (LDC) unit includes a non-linear function generator and a filter. The nonlinear function generator receives a first signal and outputs a second signal in dependence on the first signal and a transfer function of the nonlinear function generator. The filter is fed in dependence on the second signal output by the nonlinear function generator. The first signal received by the nonlinear function generator is derived in dependence on an input signal provided to an input of the LDC unit and an output of the filter. An output of the LDC unit is derived in dependence on the first signal received by the nonlinear function generator and the second signal output by the nonlinear function generator.
摘要:
Systems and methods for minimizing performance degradation due to component mismatch in the feedback path of a digital PWM amplifier feedback loop. One embodiment comprises a digital pulse width modulated (PWM) amplifier with feedback. The amplification subsystem receives a digital audio signal and produces an analog output signal. The feedback loop produces a feedback signal based on the filtered analog output signal and modifies the digital audio signal based on the feedback signal. The feedback loop includes a filter configured to filter the analog output signal and correction circuitry configured to correct component mismatch errors introduced by the filter. In one embodiment, the correction circuitry receives a measurement of a power supply voltage, multiplies the measured voltage by a gain and adds the scaled measurement to the feedback signal to correct for the component mismatch errors.
摘要:
Systems and methods are provided for converting input data streams having variable input sample rates to an output sample rate, which systems and methods are used in processing the data streams. In one embodiment, a system includes a clock source, a counter configured to count cycles for a corresponding data stream, and a data processor. The data processor is configured to read the number of cycles counted by the counter between received frame sync signals and to convert the first data stream to the predetermined output sample rate based on the corresponding number of cycles counted.
摘要:
Systems and methods for performance improvements in digital switching amplifiers using a low delay corrector. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low delay corrector configured to receive signals output by the plant. The output of the low delay corrector is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC.
摘要:
Systems and methods for scaling the number of output channels that can be provided in an audio amplification system. In one embodiment, a digital pulse width modulation (PWM) amplification system includes multiple four-channel PWM controller chips that are interconnected to enable synchronization and transfer of digital audio data from one chip to another. Input audio signals received by each of the channels are processed by sample rate converters to generate internal audio signals that have a predetermined sample rate and format. Each of the channels is synchronized so that the internal audio signal of each channel can be processed and output by any of the other channels. The PWM controller chips are connected by a high-speed interconnect that enables the transfer of data between them. Each input audio signal can be mapped to any of the outputs and can be mixed with other input signals.
摘要:
A low delay corrector (LDC) unit includes a non-linear function generator and a filter. The nonlinear function generator receives a first signal and outputs a second signal in dependence on the first signal and a transfer function of the nonlinear function generator. The filter is fed in dependence on the second signal output by the nonlinear function generator. The first signal received by the nonlinear function generator is derived in dependence on an input signal provided to an input of the LDC unit and an output of the filter. An output of the LDC unit is derived in dependence on the first signal received by the nonlinear function generator and the second signal output by the nonlinear function generator.
摘要:
Systems and methods for performance improvements in digital switching amplifiers using low-pass filtering to reduce noise and distortion. In one embodiment, a digital pulse width modulation (PWM) amplifier includes a signal processing plant configured to receive and process an input audio signal. The amplifier also includes a low-pass filter configured to filter audio signals output by the plant. The filtered output of the plant is added to the input audio signal as feedback. The plant may consist of a modulator and power switch, a noise shaper, or any other type of plant. An analog-to-digital converter (ADC) may be provided to convert the output audio signal to a digital signal. Filtering may be implemented before or after the ADC, and a decimator may be placed after the ADC if it is an oversampling ADC.