Broadcom Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Todd Lee Brooks

Kevin Lee Miller

David S P Ho

Sherif Galal

Josephus A Van Engelen

Xicheng Jiang

David Hartman

Theodore F Rabenko

Robert J Lee

Shane Patrick Lansing

James Chi Thi

Robert M Lukas

Ramin Borazjani

Vinay Chandrasekhar

Kenneth J Unger

Eric Fogleman

Akira Ito

Agnes Woo

Jungwoo Song

Jared Welz

Anilkumar V Tammineedi

Khim Leng Low

Alex Jianzhong Chen

Khaled Abdelfattah

Nelson Ray Sollenberger

Hongwei Kong

Minsheng Wang

Yee Ling Cheung

Iuri Mehr

Min Gyu Kim

John S Walley

Li Fung Chang

Claude G Hayek

Evan S McCarthy

Hui Zheng

Steven L Caine

Jianlong Chen

I-Ning Ku

David Joseph Stoops

Sasi Kumar Arunachalam

Vinod Jayakumar

Wynstan Tong

Andy Tong

Dongtian Lu

Tay Hui Zheng

A sensor interface includes on-chip relaxation oscillator circuit and a PLL that operate cooperatively to generate a highly accurate clock signal on-chip using low-power components. A photodiode generates a current signal based on an optical signal that is representative of a sensor signal. An ADC that operates based on the highly accurate clock signal generates a digital signal based on the current signal generated by the photodiode, and a processor processed the digital signal to estimate sensor data within the sensor signal. Examples of characteristics that may be sensed can include environmental characteristics (e.g., temperature, humidity, barometric pressure, etc.) and/or biomedical characteristics (e.g., body temperature, heart rate, respiratory rate, blood pressure, etc.). If desired, an amplifier processes the photodiode-provided current signal before it is provided to the ADC. Also, one or more CDACs that generate feedback currents may be used to reduce noise sensitivity of the sensor interface.

Low-power data acquisition system and sensor interface

A system is configured to facilitate bidirectional voice communication between a number of data and/or telephony devices.

Modem with voice processing capability

A low quiescent current amplifier and driver having multiple amplifiers (e.g. Class AB and B amplifiers) work in concert to independently amplify all or a portion of a signal into multiple amplified signals combined into a unified signal. Operation of a second amplifier is slaved to operation of a first amplifier. Each amplifier may have its own feedback loop providing the same gain transfer function to align transitions of the multiple amplified signals. Operation of the first amplifier may be detected using a replica of a signal, stage or transconductance in the first amplifier. At the same threshold, operation of the first and second amplifiers may be transitioned, e.g., the second amplifier may transition between providing increasing or decreasing current and providing zero current while the first amplifier may transition between providing constant current and providing increasing or decreasing current.

Low-quiescent current headset driver

A network gateway is configured to facilitate on line and off line bi-directional communication between a number of near end data and telephony devices with far end data termination devices via a hybrid fiber coaxial network and a cable modem termination system. The described network gateway combines a QAM receiver, a transmitter, a DOCSIS MAC, a CPU, a voice and audio processor, a voice synchronizer, an Ethernet MAC, and a USB controller to provide high performance and robust operation.

A multi-rate sigma delta digital-to-analog converter may include a signal input and a signal output, and multiple modulators. A first of the modulator may convert a digital input signal on the signal input to an analog output signal on the signal output. Subsequent of the multiple modulators may shape and cancel quantization noise received from a proceeding modulator. One of the modulators may operate at a higher frequency than does another of the multiple modulation loops.

Multi-rate sigma delta digital-to-analog converter

Disclosed is a power-efficient multi-mode charge pump. The charge pump comprises a first pumping circuit that provides at least one output voltage produced by a discharge sequence of a shared flyback capacitor. The charge pump also comprises a second pumping circuit that provides a plurality of output voltages produced by a corresponding plurality of discharge sequences of the shared flyback capacitor. The charge pump may include a transition circuit to selectably enable the first pumping circuit or the second pumping circuit. In one embodiment, the first pumping circuit may employ a two-phase discharge sequence. In another embodiment, the second pumping circuit may employ a three-phase plurality of discharge sequences. A related method is also disclosed.

Power-efficient multi-mode charge pump

Disclosed is a Class-AB/B amplifier comprising a first output stage including a first plurality of amplification devices and a second output stage including a second plurality of amplification devices. According to one embodiment, the first output stage operates when the Class-AB/B amplifier is in a quiescent state and the second output stage operates when the Class-AB/B amplifier is in an active state. The Class-AB/B amplifier also comprises a level shifting circuit that adjusts a control voltage of the second output stage, where the level shifting circuit is adapted to activate the second output stage when the Class-AB/B amplifier enters the active state. Embodiments of the Class-AB/B amplifier may include a level shifting circuit that implements either a fixed or signal-dependent level shift, and a quiescent control circuit that substantially eliminates any systematic offset arising from the active feedback circuit inside the replica bias circuit.

Quiescent control circuit for providing control current for an amplifier

Class-AB/B amplifier with quiescent control circuit

Disclosed is an amplifier designed to substantially reduce an ON/OFF transient. The amplifier comprises a drive block that includes a pre-driver and an output stage. The amplifier also comprises a bypass circuit that is coupled to an output of the pre-driver. The bypass circuit of the amplifier is selectively activated to reduce the ON/OFF transient. The bypass circuit may comprise an auxiliary output stage that can be coupled to provide selective activation. The amplifier may also be configured to provide multi-point offset compensation. Also disclosed is a related method. The amplifier and the related method may be incorporated into an audio amplifier used in a cellular telephone or other mobile audio device.

Amplifier with reduced on/off transient and multi-point offset compensation

Aspects of a method and system for detecting and identifying electronic accessories or peripherals utilizing a hardware audio CODEC are provided. In this regard, a hardware audio CODEC may be operable to compare one or more voltages on one or more biased pins of an accessory or peripheral port to one or more reference voltages and generate one or more digital representations of the one or more voltages on the biased one or more pins. An accessory or peripheral attached to the accessory or peripheral port may be identified based on the comparison and/or the generated one or more digital representations. The one or more bias voltages may be controlled based on a result of the comparison and/or the generated digital representations. The one or more bias voltages may be reduced after an attached accessory or peripheral has been identified.

Method and system for detecting and identifying electronic accessories or peripherals

Aspects of a method and system for compensating temperature readings from a temperature sensing crystal integrated circuit are provided. An electronic device may digitize a temperature indication received from a temperature sensing circuit, digitize one or more calibration voltages received from said temperature sensing circuit, and calculate a compensated temperature indication utilizing the digitized calibration voltage(s), and the digitized temperature indication, and data from a table that characterizes behavior of the temperature sensing circuit as a function of temperature. One or more circuits in the electronic device may be controlled based on the compensated temperature indication. The compensated temperature indication may compensate for a gain error and/or offset error of a digital to analog converter that digitizes the temperature indication and the calibration voltage(s). There may be two calibration voltages.

Method and system for compensating temperature readings from a temperature sensing crystal integrated circuit

Class-AB/B amplifier and quiescent control circuit for implementation with same

Disclosed is a switching amplifier having an enhanced supply rejection. The switching amplifier comprises a digital modulator that provides a modulated signal. The switching amplifier further comprises a closed-loop analog driver that is coupled to the digital modulator. As disclosed, the closed-loop analog driver is configured to re-modulate a modulation signal that corresponds to the modulated signal. An output stage of the switching amplifier is driven by the re-modulated signal, thereby providing enhanced supply rejection. In one embodiment, the modulated signal is produced by a digital pulse-width modulator (PWM) circuit of a Class-D amplifier, and has a pulse rate substantially less than a clock rate of the digital PWM circuit. In one embodiment, the switching amplifier is implemented as an audio amplifier in a mobile communication device such as a cellular telephone.

Switching amplifier with enhanced supply rejection and related method

Disclosed is a closed-loop class-D amplifier circuit including a modulated reference signal generator that provides a modulated reference signal in a feed-forward path, where the reference signal is modulated corresponding to an input signal. The closed-loop class-D amplifier circuit further includes a comparator to generate a control signal based on a comparison of the modulated reference signal and a correction signal, which in turn is produced by filtering a combination of the input signal and a feedback signal. The closed-loop class-D amplifier circuit also includes a pulse generator to generate a pulse-width-modulated signal to drive an output stage of the closed-loop class-D amplifier based on the control signal.

Closed-loop class-D amplifier with modulated reference signal and related method

Growing community of inventors

Laguna Beach, CA, United States of America

Todd Lee Brooks