Xilinx, Inc.

Other

University of California

Ut-battelle, Inc.

The University of Tennessee Research Foundation

Infinera Corporation

Vassili Kireev

James Karp

Albert Vareljian

Toan D Tran

Parag Upadhyaya

Hsung Jai Im

Jafar Savoj

Yu Liao

Ephrem C Wu

John K Jennings

Michael O Jenkins

Patrick J Quinn

Fu-Tai An

Mark J Marlett

Yehuda Braiman

Jeffrey Bostak

Yun Liu

Vladimir Protopopescu

Vijay Gupta

Somnath Kundu

An adaptive analog parallel combiner circuit for receiver data recovery from a communication signal is provided. The circuit includes a summer that sums outputs of a plurality of filter taps in parallel, including zeroth and first through Nth filter taps, each filter tap having as input the communication signal or a version thereof, wherein N is a finite integer greater than or equal to two. The zeroth filter tap has an amplifier with gain controlled by a zeroth adaptive gain control coefficient, and each of the first through Nth filter taps having an all pass filter and gain controlled amplification, with gain controlled by a corresponding one of a first through Nth adaptive gain control coefficients and the all pass filter implementing a transfer function having a zero and a pole equaling each other and at a base frequency divided by a corresponding integer from one through N.

Adaptive analog parallel combiner

A decision feedback equalizer (DFE) is provided. The DFE includes an analog front end, configured to receive a digital communication signal having amplitude modulation greater than two-level, and to output a feedforward signal based on the digital communication signal. The DFE includes a summing block, configured to receive the feedforward signal, a plurality of delayed data decisions as digital signals, and a plurality of adapted coefficients. The summing block is configured to produce an analog feedback signal as an analog subtraction from the feedforward signal of each of the plurality of delayed data decisions multiplied by a corresponding one of the plurality of adapted coefficients. The DFE includes a delay chain configured to produce the plurality of delayed data decisions based on the analog feedback signal, each of the plurality of delayed data decisions having two or more bits, corresponding to the amplitude modulation being greater than two-level.

Full bridge decision feedback equalizer

A transmitter circuit for generating a modulated signal in a transmitter of an integrated circuit is described. The transmitter circuit comprises a multiplexing stage having a multiplexing circuit configured to receive a differential input signal and to generate a differential output signal at a first output node of a first current path and at a second output node of a second current path, the multiplexing stage having a gain circuit configured to increase the swing of the differential output signal generated at the first output node and the second output node. A method of generating a modulated signal in a transmitter of an integrated circuit is also disclosed.

Transmitter circuit for and methods of generating a modulated signal in a transmitter

A scaling apparatus and method for compensating nonlinearity due to the finite output impedance of current sources in current-steering digital-to-analog converters (DACs) are disclosed herein. In an example, a DAC may receive a digital input signal. The DAC may determine an output current weight for each of a plurality of unit cells, based on an output impedance of the unit cell. Further, the DAC may generate an analog output signal by applying the plurality of output current weights to the digital input signal. Then, the DAC may output the analog output signal. The analog output signal may be a high frequency analog output signal, which may be an optical high frequency analog output signal. In an example, a transfer curve of the analog output signal may be linear in terms of analog output signal voltage versus digital input code. The output current weights may include one or more polynomial terms.

Scaling apparatus and method for compensating nonlinearity due to the finite output impedance of current sources in current-steering digital-to-analog converters

A circuit for generating a modulated signal in a transmitter of an integrated circuit is disclosed. The circuit comprises a transmitter driver circuit having a first current path for receiving a first input signal of a pair of differential input signals and a second current path for receiving a second input signal of the pair of differential input signals, the transmitter driver circuit comprising a tail current path coupled to each of the first current path and the second current path; a first current source coupled between a first reference voltage and ground, wherein a first current of the first current source is proportional to the tail current of the tail current path; a first pull-up current source coupled between the first reference voltage and a first output node of the transmitter driver circuit; and a second pull-up current source coupled between the first reference voltage and a second output node of the transmitter driver circuit. A method of generating a modulated signal in a transmitter of an integrated circuit is also disclosed.

Circuits for and methods of generating a modulated signal in a transmitter

Various example implementations are directed to circuits and methods for inter-die communication on a multi-die integrated circuit (IC) package. According to an example implementation, an IC package includes a first semiconductor die having a plurality of communication circuits for communicating data over respective data terminals of the package. The package also includes a second semiconductor die having N contacts for communicating data to and from the semiconductor die. The second semiconductor die includes a logic circuit configured to communicate M parallel data signals with one or more other semiconductor dies of the package, wherein M&#x3e;N. The second semiconductor die also includes a plurality of serializer circuits, each configured to serialize data from a respective subset of the plurality of the M signal lines to produce serialized data and provide the serialized data to a respective one of the contacts.

Method and circuits for communication in multi-die packages

An inductor for an integrated circuit can include a first turn comprising a first through silicon via (TSV) coupled to a second TSV. The inductor can include a third TSV coupled to the second TSV.

Inductive structure formed using through silicon vias

In one example, an oscillator circuit includes: a master oscillator comprising a master LC tank coupled to a master active circuit, the master LC tank including a primary winding of a transformer and a capacitance; a slave oscillator comprising a slave LC tank coupled to a slave active circuit, the slave LC tank including a secondary winding of the transformer and a capacitance; and a first pair of coupling transistors and a second pair of coupling transistors each coupling the master oscillator to the slave oscillator. Gates of the first pair of coupling transistors are coupled to the master oscillator through a switch. Gates of the second pair of coupling transistors are coupled to the master oscillator through respective ninety-degree phase shifters and the switch.

LC oscillator circuit with wide tuning range

An integrated circuit and method for providing a differential transmission line driver are disclosed. One embodiment of the differential transmission line driver comprises a current mode logic (CML) stage, and a cross-coupled n-channel enhancement type metal-oxide semiconductor field-effect transistor (NMOS) stage, wherein the cross-coupled NMOS stage provides a feedback current to the CML stage, where each output voltage of the differential transmission line driver is characterized by symmetrical rising and falling edges.

Method and apparatus for providing a differential output driver with a cross-coupled cell

An inductor implemented in an integrated circuit is described. The inductor comprises a plurality of loops of the inductor in at least a first metal layer and a second metal layer of a plurality of metal layers; and a plurality of vias connecting ends of loops of the plurality of loops in different metal layers; wherein each loop of the first metal layer which is connected to a corresponding loop of the second metal layer overlies the corresponding loop of the second metal layer. A method of implementing an inductor in an integrated circuit is also described.

Stacked inductor structure

A circuit for implementing a gain stage in an integrated circuit is described. The circuit comprises a first inductor formed in a first plurality of metal layers; a second inductor formed in a second plurality of metal layers, the second inductor coupled to a center tap of the first inductor; and wherein the second inductor has a diameter that is less than a diameter of the first inductor. A method of implementing a gain stage in an integrated circuit is also described.

Growing community of inventors

Sunnyvale, CA, United States of America

Vassili Kireev