Avago Technologies General IP (Singapore) Pte. Ltd.

Avago Technologies Ecbu IP (Singapore) Pte. Ltd.

Robert M Thelen

Robert Elsheimer

Brian James Misek

Michael Farmer

Jade M Kizer

Peter Henry Mahowald

Zachary T Deitz

Robert H Miller, Jr

Robert Keith Barnes

Thomas M Walley

Herman H Pang

A receiver termination circuit includes an internal AC coupling capacitor and an adjustable resistor forming an adjustable high-pass filter (HPF) at a receiver side of a transmission medium, and a digital-to-analog converter (DAC) coupled to the adjustable HPF, the DAC configured to provide a signal having a low-pass filter response to the adjustable HPF to provide a DC restore function.

System and method for internal AC coupling with active DC restore and adjustable high-pass filter for a PAM 2/4 receiver

An active termination circuit for a differential receiver includes a first receiver element configured to receive a first component of a differential signal, a second receiver element configured to receive a second component of a differential signal, a common mode measurement element configured to receive the differential signal and generate a transmit common mode signal (Vcm) representing an average value of the differential signal, and a receiver (RX) common mode signal node. The termination circuit also comprises an active element configured to receive the transmit common mode signal (Vcm) and provide an output to the receiver common mode signal node, the output configured to drive the value of the signal at the receiver common mode signal node to the value of the transmit common mode signal (Vcm), and a capacitive element coupled to the receiver common mode signal node in parallel with the active element.

System and method to actively drive the common mode voltage of a receiver termination network

A circuit for skewing differential signals includes a coarse adjustment stage configured to receive a differential input signal having a true component and a complement component, the coarse adjustment stage configured to impart a first controllable delay to at least one of the true component and the complement component of the differential signal, and a fine adjustment stage configured to impart a second controllable delay to at least one of the true component and the complement component of the differential signal, the second controllable delay having a resolution different than a resolution of the first controllable delay, the first controllable delay and the second controllable delay providing a timing skew between the true component and the complement component of the differential signal.

System and method for pre-skewing timing of differential signals

In a phase-locked loop (PLL) calibration system and method, the PLL input reference clock is phase-modulated, the resulting PLL output modulation is measured, and PLL calibration signals, such as a PLL proportional path adjustment signal and a PLL integral path adjustment signal, are derived from the measured PLL output modulation.

Phase-locked loop calibration system and method

A gain control circuit, suitable for controlling the amplitude of a voltage-controlled oscillator, includes a duty cycle detector, an analog-to-digital converter, and a function generator. The gain control circuit provides a digitally enabled negative feedback loop. The duty cycle detector generates an estimate of the amplitude. The function generator receives a target amplitude as well as a digital representation of the estimate of the amplitude. The function generator calculates a modified estimate and periodically compares the same to the target value to generate a control word. The control word is arranged to enable current sources in the voltage-controlled oscillator.

Digital automatic gain control circuits and methods for controlling the amplitude of a time-varying signal

A method of capturing user control inputs for an electronic device comprises sampling an input measurement signal at a capacitive input sensor of the electronic device to capture user control inputs for operating the electronic device. Electromagnetic interference affecting the sampling or the input measurement signal is electronically neutralized.

Neutralizing electromagentic noise for a capacitive input device

A method of capturing user control inputs for an electronic device comprises sampling an input measurement signal at a capacitive input sensor of the electronic device to capture user control inputs for operating the electronic device. Electromagnetic interference affecting the sampling of the input measurement signal is electronically neutralized.

Neutralizing electromagnetic noise for a capacitive input device

A driver circuit for driving a light source of an optical pointing device includes a first transistor coupled to the light source. The driver circuit includes a controller coupled to the first transistor for monitoring a first current through the light source, comparing the first current to a reference current, and generating a control signal based on a result of the comparison, wherein the control signal causes the first transistor to change the first current.

Driver circuit for driving a light source of an optical pointing device

Driver circuit that generates an output drive signal that can be used to drive a light source (e.g., a light emitting diode (LED)) is described. The driver circuit includes an output transistor that operates in either a saturation region or a triode region. The driver circuit employs feedback to generate an output drive signal (e.g., an output drive current) that is independent on the operating mode of the output transistor.

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Fort Collins, CO, United States of America

Robert M Thelen