Patent ID: 7493179

Claim:
A digital audio system, comprising: a digital audio processor for receiving and processing a digital audio signal to generate a processed digital audio signal; and a digital volume control, coupled to the digital audio processor, the digital volume control comprising: a first summation unit having a first input for receiving the processed audio signal, a second input for receiving a frequency shaped error signal; and an output for providing a composite digital audio signal; an attenuator having an input for receiving the composite digital audio signal, and in response, the attenuator providing an attenuated digital audio signal at an output; an error determination unit having an input coupled to the output of the attenuator, the error determination unit for determining an error induced in the attenuated digital audio signal by the attenuator; and a filter having an input coupled to an output of the error determination unit, for receiving the error, and in response, providing the frequency shaped error signal to the second input of the first summation unit; wherein the error determination unit comprises: a multiplier having a first input for receiving the attenuated digital audio signal, a second input for receiving an attenuation factor, and an output for providing an intermediate result; and a second summation unit having a first input for receiving the intermediate result, a second input for receiving the composite digital audio signal, and an output for providing the error.