Patent ID: 8306245

Claim:
A multimode audio amplifier comprising: a mode controller configured to provide a control signal; at least one multimode module, wherein each of the multimode modules is configured to operate in one of a plurality of operating modes, wherein the operating modes are selected in response to the control signal, wherein changing the operating modes results in a measurable change in at least one characteristic of the multimode audio amplifier, and wherein the characteristics of the multimode audio amplifier include signal to noise ratio (SNR), total harmonic distortion and noise (THD+N), input to output delay, power consumption, and efficiency; and a variable-length finite impulse response (FIR) filter configured to provide an output signal based on an input signal, wherein a length of the variable-length FIR filter is selected in response to the control signal, wherein the length of the variable-length FIR filter represents at least one of an order of the variable-length FIR filter, and a number of taps of the variable-length FIR filter, and wherein the variable-length FIR filter comprises a first fixed-length FIR filter configured to provide a first filtered signal based on the input signal, a second fixed-length FIR filter configured to provide a second filtered signal based on the first filtered signal, and an output module configured to provide one of the first filtered signal and the second filtered signal as the output signal in response to the control signal.