Patent ID: 7899196
Filing Date: 2011-03-01
Classification: H03F,H04R

Abstract:
1. An integrated circuit, configured to process microphone signals, where the integrated circuit comprises: a preamplifier with an amplifier section which has a differential input comprising a first input (+) and a second input (−) and an output (φ; φ*), and with a feedback filter network coupled between the output (φ; φ*) and the second input (−); where the first input (+) to the amplifier section is coupled to an input (φ)) of the preamplifier for receiving a microphone signal; and where the preamplifier has a frequency-gain transfer function which suppresses low frequencies in a stop band relative to higher frequencies in a pass band; and where the preamplifier is configured to provide a common-mode differential output signal in the stop band and a differential-mode differential output signal in the pass band; and an analogue-to-digital converter coupled to receive the differential output signal, as an anti-aliasing filtered signal, from the preamplifier and to provide a digital output signal.