Sigmatel, Inc.

Maxim Integrated Products, Inc.

Freescale Semiconductor,inc.

The University of Texas System

Matthew Derrell Felder

Michael R May

Marcus William May

Matthew Brady Henson

Brian David Trotter

Daniel Patrick Mulligan

Russell Alvin Schultz

Mark Alan Summers

James Mason

Brian L Evans

Charles Eric Seaberg

Lawrence Ragan

Thomas Glen Ragan

Euan Patrick Murphy

Jeffrey Lee Lo

Douglas Edward Heineman

Bryan Mo

Jingyu Hu

Jamie Joseph Happ

Systems and methods reduce unwanted effects caused by mismatch in amplifier circuits having components that are trimmable during and post-production to minimize DC offset. Various embodiments of the invention trim out amplifier mismatch by determining trim codes for two or more phases of operation of an amplifier circuit and use those trim codes to determine a final trim code for use in regular operation.

Auto-calibration systems and methods for reducing amplifier offset

A method and apparatus can include: audio interface pins coupled to swappable connections including a BCLK, an LRCLK, a DIN, and a DOUT; a BCLK determiner configured to identify the BCLK as the swappable connection with a highest frequency; an LRCLK determiner configured to: measure cycle lengths, compare the cycle lengths to a pre-defined multiple, identify the LRCLK as the swappable connections, and output an association between the LRCLK and one of the audio interface pins; and a mode determiner configured to identify and output a mode based on the association of the BCLK to the audio interface pins and the association of the LRCLK to the audio interface pins.

Pin encoded mode selection system

A method for developing TDM data with embedded control data includes obtaining signal data and control data, formatting the signal data and the control data into a plurality of channels of a DIN signal, and transmitting the DIN signal on one line of a 3-bit TDM bus. A multichannel input device includes a control extractor receptive to the three-bit TDM bus and operative to extract CNTL data from the DIN data, a DAI receptive to the 3-bit TDM bus and the channel select input and operative to develop a SIGNAL data output, and a DAC block including a DAC, the DAC block being receptive to the SIGNAL data and the CNTL data.

Method and apparatus for controlling a multichannel TDM device

A multichannel input device with automatic number-of-channels detection includes an automatic channel and bit depth detector, a digital audio interface (DAI), an analog device, and a digital-to-analog converter (DAC) coupling the DAI to the analog device. The automatic number-of-channels and bit depth detector has a BCLK input, a LRCLK input, a number of channels NCHAN output, and a bit depth B output. The DAI has a data DIN input, the BCLK input, the LRCLK input, an NCHAN input and a B input and has an output including data associated with an assigned channel.

Multichannel digital audio interface

Various embodiments of the present invention relate to systems, devices and methods of oversampling electronic components where high frequency oversampling clock signals are generated internally. The generated oversampling clock is automatically synchronous with the input clock and the input serial data in a serial data link, and is adaptive to predetermined parameters, such as bit depth and oversampling rate.

Adaptive frequency synthesis for a serial data interface

An audio output circuit includes an on-chip left channel amplifier module, an on-chip center channel amplifier module, and an on-chip right channel amplifier module. A left channel IC pin is operably coupled to an output of the on-chip left channel amplifier module. A right channel IC pin is operably coupled to an output of the on-chip right channel amplifier module. A center channel IC pin is operably coupled to an output of the on-chip center channel amplifier module. A center channel feedback IC pin is operably coupled to an input of the on-chip center channel amplifier module to provide a feedback loop. A left jack connection is operably coupled to the left channel IC pin. A right jack connection is operably coupled to the right channel IC pin. A jack return connection coupled to the center feedback IC pin. An inductor has a first node coupled to the jack return connection and a second node coupled to the center channel IC pin.

Audio output driver for reducing electromagnetic interference and improving audio channel performance

A gain control module includes an amplifier, a least significant bit (LSB) gain stage, and a most significant bit (MSB) gain stage. The amplifier includes a first input, a second input, and an output. The LSB gain stage produces a LSB gain based on an LSB portion of a gain control signal, wherein the LSB gain stage receives an input signal. The MSB gain stage produces an MSB gain based on an MSB portion of the gain control signal, wherein the MSB gain stage is coupled to the LSB gain stage, the first input of the amplifier, and the output of the amplifier, wherein the gain control module amplifies the input signal in accordance with the gain control signal.

Gain control module and applications thereof

A digital to analog converter (DAC) includes: first and second nodes; a first switching device; a second switching device; and a switch control module. The switch control module selectively configures the first and second switching devices such that: in a first configuration, the first switching device connects a first current to the first node and the second switching device connects a second current to the second node; in a second configuration, the first switching device connects the first current to the second node and the second switching device connects the second current to the first node; and in a third configuration, the first and second switching devices disconnect the first current and the second current from the first and second nodes.

Digital to analog converters with adjustable output resolution

A touch screen driver that can be used with a resistive touch screen includes an input/output module that supplies at least one input signal to at least one of a plurality of input/output ports of the touch screen and that generates at least one output signal, in response to the at least one input signal, and in accordance with at least one control signal. A controller module generates the at least one control signal and that generates a position signal representing a resolved position in accordance with a plurality of contemporaneous touches of the resistive touch screen.

Touch screen driver for resolving plural contemporaneous touches and methods for use therewith

A headphone driver includes a driver module for generating a plurality of headphone driver signals including a filtered stereo sum signal.

Headphone driver and methods for use therewith

A system-on-a-chip integrated circuit includes a multimedia module that produces rendered output data and a high-speed interface. A processing module generates output multimedia data in accordance with at least a portion of a multimedia application in response to input multimedia data received from either the multimedia module or the high-speed interface. The output multimedia data is provided to either the multimedia module or the high-speed interface. An on-chip DC-to-DC converter converts a battery voltage into a supply voltage that is coupled to the multimedia module, the high-speed interface, and/or the processing module.

Growing community of inventors

Austin, TX, United States of America

Matthew Derrell Felder