National Semiconductor Corporation

Knowles Electronics, Inc.

Adam Abed

Niel David Warren

Ansuya P Bhatt

Raminder Jit Singh

Donald T Sanders

David A Beeson

Edwin Cordon

Maulik Patel

Dushyant Liya

A microphone assembly includes a housing including a base, a cover, and a sound port. The microphone assembly further includes an acoustic transducer and an electrical circuit, both of which are disposed in an enclosed volume of the housing. The transducer and electrical circuit work in concert to convert sound waves into a processed digital audio signal. The electrical circuit is configured to process digital data in a series of frames that correspond to a fixed period in time. The electrical circuit is further configured to reduce noise in the resulting signal by varying the current draw required in a randomized or pseudo-randomized fashion between adjacent frames of digital data.

Digital microphone with reduced processing noise

A circuit and method for signal amplification is provided. The circuit includes an amplifier including an input amplifier that is arranged to receive an input analog signal, and to provide an input amplifier output signal by amplifying the input analog signal. The amplifier further includes a DC offset correction circuit that is arranged to determine a DC offset correction for the input amplifier each time the amplifier is powered up. The DC offset correction is performed by iteratively adjusting a DC offset of the input amplifier until the input amplifier output DC offset is zero when the input analog AC signal is zero, within a predetermined tolerance. The DC offset correction circuit is further arranged to provide the determined DC offset correction to the input amplifier during operation of the amplifier.

Apparatus and method for complete elimination of input coupling capacitors in signal amplification

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Sunnyvale, CA, United States of America

Adam Abed