Rambus Inc.

Finsix Corporation

Massachusetts Institute of Technology

The General Hospital Corporation

Highlands Corporation

Fred F Chen

Vladimir Marko Stojanovic

Jared L Zerbe

Andrew P Ho

Elad Alon

Mark A Horowitz

Anthony G Bessios

Bruno Werner Garlepp

Andrew C Ho

Brian S Leibowitz

John Wood Poulton

Kevin S Donnelly

Ramin Farjad-Rad

Anthony D Sagneri

Justin Burkhart

Andrew C C Ho

Jae-Won George Hwang

George Hwang

Carl William Werner

William Franklin Stonecypher

Hongshen Ma

Robert L Sheridan

Pei-Lan Hsu

Henry Wu

Brad Stronger

Brian Lebowitz

Vladimir M Stojanovis

A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.

High-speed signaling systems with adaptable pre-emphasis and equalization

A high-speed signaling system with adaptive transmit pre-emphasis. A transmit circuit has a plurality of output drivers to output a first signal onto a signal path. A receive circuit is coupled to receive the first signal via the signal path and configured to generate an indication of whether the first signal exceeds a threshold level. A first threshold control circuit is coupled to receive the indication from the receive circuit and configured to adjust the threshold level according to whether the first signal exceeds the threshold level. A drive strength control circuit is coupled to receive the indication from the receive circuit and configured to adjust a drive strength of at least one output driver of the plurality of output drivers according to whether the first signal exceeds the threshold level.

High speed signaling system with adaptive transmit pre-emphasis

A signaling circuit having a selectable-tap equalizer. The signaling circuit includes a buffer, a select circuit and an equalizing circuit. The buffer is used to store a plurality of data values that correspond to data signals transmitted on a signaling path during a first time interval. The select circuit is coupled to the buffer to select a subset of data values from the plurality of data values according to a select value. The equalizing circuit is coupled to receive the subset of data values from the select circuit and is adapted to adjust, according to the subset of data values, a signal level that corresponds to a data signal transmitted on the signaling path during a second time interval.

Selectable-tap equalizer

Described are methods and circuits for margin testing digital receivers. These methods and circuits prevent margins from collapsing in response to erroneously received data and can thus be used in receivers that employ historical data to reduce intersymbol interference (ISI). Some embodiments detect receive errors for input data streams of unknown patterns and can thus be used for in-system margin testing. Such systems can be adapted to dynamically alter system parameters during device operation to maintain adequate margins despite fluctuations in the system noise environment due to e.g. temperature and supply-voltage changes. Also described are methods of plotting and interpreting filtered and unfiltered error data generated by the disclosed methods and circuits. Some embodiments filter error data to facilitate pattern-specific margin testing.

Margin test methods and circuits

In an aspect, the present invention provides a high frequency switching power converter. The high frequency switching power converter may include a plurality of soft-switchable power cells flexibly connected to receive an input signal in series and provide an output. The high frequency switching power converter may further include a controller for configuring the flexible connection and for controlling the power cells to receive the input signal. In an embodiment, each of the plurality of power cells may be separately controllable by the controller. Further, a portion of the plurality of power cells may be arranged with parallel outputs. Additionally, at least one of the plurality of cells may include one or more switched capacitors. In another embodiment, the at least one of the plurality of cells may include at least one switched capacitor and a DC/DC regulating converter.

Multi-path power factor correction

Selectabe-tap equalizer

Growing community of inventors

San Francisco, CA, United States of America

Fred F Chen