Freescale Semiconductor,inc.

Microchip Technology Inc.

Christian J Rotchford

Michael L Gomez

Leo G Dehner

Brandt Braswell

Ronald Clayton Alford

Gerald P Miaille

John Sisto

Richard B Meador

Jiangbo Gan

Boris Razmyslovitch

Jeff Ganger

Niall Duncan

A USB interface to provide power delivery negotiated through a dedicated transmission channel includes a transmitter circuit including a digital-to-analog converter having an output coupled with an input of a transmission filter, a receiver circuit including an analog-to-digital converter having an input coupled with an output of a receiving filter, and a switching circuit configured in an operating mode of the USB interface to connect an output of the transmission filter and an input of the receiving filter to a connection node of the dedicated transmission channel.

Method and apparatus for providing USB power delivery negotiated through a dedicated transmission channel

A technique for calibrating a transceiver of a wireless communication device includes selectively coupling an output node of a transmitter of the transceiver to an input node of a receiver of the transceiver. A calibration signal is provided, from the output node of the transmitter, to the input node of the receiver. The calibration signal is down-converted, with the receiver, to provide a down-converted calibration signal. A discrete Fourier transform is performed on the down-converted calibration signal. Finally, one or more correction factors are determined based on an analysis of the discrete Fourier transform of the down-converted calibration signal. At least one of the correction factors is utilized to facilitate substantial cancellation of a direct current offset associated with the transceiver.

Techniques for calibrating a transceiver of a communication device

An embodiment of a baseband filter in a transmitter subsystem of a wireless device comprises an operational amplifier (op-amp), a pole circuit, a feedback capacitor, and an active device. The op-amp is adapted to produce an amplified signal that includes noise gain produced by the op-amp. The pole circuit is electrically coupled with an output terminal of the op-amp, and is adapted to receive the amplified signal and to attenuate the noise gain to produce a filtered, amplified signal. The feedback capacitor is electrically coupled between the first pole circuit and an input terminal of the op-amp, and is adapted to compensate for a phase shift produced by the pole circuit. The active device is electrically coupled with the pole circuit, and is adapted to amplify the filtered, amplified signal and to produce a baseband filtered output signal.

Baseband filters for use in wireless communication devices

Methods and corresponding systems for calibrating a digital-to-analog converter include selecting first and second code regions in the digital-to-analog converter, wherein the first and second code regions are separated by a boundary. Thereafter a waveform sequence is input into the digital-to-analog converter, wherein the waveform sequence has a zero offset at the boundary. Then a relative compensation value between the first and second code regions is adjusted to reduce a distortion in an output of the digital-to-analog converter. A magnitude of a third harmonic distortion of the waveform sequence can be used to measure distortion in the output. Adjusting the relative compensation can include converting the output of the digital-to-analog converter to a digital sequence, filtering the digital sequence, and measuring a harmonic distortion in the digital sequence.

Calibrating a digital-to-analog converter

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Austin, TX, United States of America

Christian J Rotchford