Method and device including signal processing for pulse width modulation
AssigneeSamsung Electronics Co., Ltd.
InventorBong Joo Kim
Life of this patent
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Abstract
A method and system process a signal for PWM modulation. An amplitude control signal adjusts the amplitude of an input signal, and an offset is added to the amplitude-adjusted signal to produce an offset-adjusted signal. The offset is selected according to the amplitude adjustment applied to the input signal. The offset-adjusted signal is pulse-width modulated the to produce a pulse-width modulated signal, and the pulse-width modulated signal is filtered to reduce high frequency components thereof.
Claims36
A method, comprising:
- receiving a pulse code modulated (PCM) audio signal in an amplifier circuit;
- adjusting the PCM audio signal in response to a volume control signal to generate a PCM volume-controlled audio signal;
- generating an offset value in response to the volume control signal;
- combining the offset value with the PCM volume-controlled audio signal to generate an offset-adjusted volume-controlled PCM audio signal;
- pulse-width modulating the offset-adjusted volume-controlled PCM audio signal to generate a pulse-width modulated signal;
- and
- filtering the pulse-width modulated signal to generate an analog audio output signal output by the amplifier circuit.
A method of processing an input signal in an amplifier circuit, the method comprising:
- pulse-width modulating the input signal received in the amplifier circuit using a pulse-width modulator (PWM) to generate a PWM signal;
- filtering the PWM signal to reduce high frequency components;
- adjusting a duty ratio of the PWM signal in response to an amplitude control signal by increasing the duty ratio of the PWM signal to be greater than 1:1 when the amplitude control signal is less than a defined maximum value, and
- providing an output signal derived from the duty ratio-adjusted PWM signal from the amplifier circuit.
A method of processing an input audio signal in an amplifier circuit receiving a volume control signal, the method comprising:
- pulse-width modulating the input audio signal using a pulse-width modulator (PWM) to generate a PWM audio signal;
- filtering the PWM audio signal to reduce high frequency components;
- and
- adjusting a duty ratio of the PWM audio signal by applying an offset to the input audio signal selected in response to the volume control signal.
Dependencies are inferred from the claim text.