Amplifier circuitry, integrated circuit and communication unit

摘要

Amplifier circuitry comprising a class-D amplifier for amplifying an audio input signal. The amplifier circuitry comprises sigma-delta modulation logic arranged to receive the audio input signal and to generate a modulated signal representative of the audio input signal, and an output stage arranged to generate an output signal for the amplifier circuitry. The amplifier circuitry further comprises finite impulse response, filter logic operably coupled between the modulation logic and the output stage, and having at least one zero in its transfer function arranged to substantially pass signal components within the modulated signal occurring at frequencies less than the at least one zero and to attenuate signal components within the modulated signal at frequencies greater than the at least one zero.