Inphi Corporation

Pmc-sierra, Inc.

Marvell Asia Pte., Ltd.

Pmc-sierra Us, Inc.

Dragos Cartina

Jamal Riani

Yu Liao

ChangFeng Loi

William Michael Lye

Jurgen Hissen

Wen-sin Liew

Wen-Sin Liew

Ankit Bhargav

A transmitter includes a shift register, a lookup table, and a digital to analog converter. The shift register is configured to receive an input signal and to output delayed copies of the input signal. The lookup table is configured to store compensation values estimated based on the input signal and the delayed copies of the input signal. The digital to analog converter is configured to output a transmit signal based on the input signal and the compensation values. The compensation values are designed to mitigate distortion of the transmit signal from conversion of the input signal to a digital signal.

Method and device for digital compensation of dynamic distortion in high-speed transmitters

A device and method of operation for digital compensation of dynamic distortion. The transmitter device includes at least a digital-to-analog converter (DAC) connected to a lookup table (LUT), a first shift register, and a second shift register. The method includes iteratively adjusting the input values via the LUT to induce changes in the DAC output that compensate for dynamic distortion, which depends on precursors, current cursors, and postcursors. More specifically, the method includes producing and capturing average output values for each possible sequence of three symbols using the shift register and LUT configuration. Then, the LUT is updated with estimated values to induce desired output values that are adjusted to eliminate clipping. These steps are performed iteratively until one or more check conditions are satisfied. This method can also be combined with techniques such as equalization, eye modulation, and amplitude scaling to introduce desirable output signal characteristics.

The present invention is directed to communication systems and methods thereof. More specifically, an embodiment of the present invention includes a buffer that is coupled to a reference terminal. A shift register stores decision levels for post-cursor positions. A plurality of switches converts the decision levels to equalization currents during an equalization process. The equalization currents are converted to equalization voltage terms by one or more load resistors. The buffer is provided between the reference terminal and the one or more load resistors. There are other embodiments as well.

Decision feedback equalizer for single-ended signals to reduce inter-symbol interference

Provided is a method and apparatus for aligning a first local oscillator (LO) clock generated by a controllable LO clock generator in a first radio frequency (RF) path with a second LO clock in a second RF path. The apparatus includes a synchronization channel configured to exchange a synchronization clock between the first and second RF paths, a phase detector configured to measure a phase alignment between the first and second LO clocks, and a loop filter configured to drive the controllable LO clock generators using the phase alignment. Also provided is a time to digital converter. The time to digital converter includes a D flip-flop for sampling first and second input clocks with a third clock, and a counter configured to synchronously increment the resulting samples and create a digital proportional value representing the delay between the first and second clocks.

System and method for synchronizing local oscillators

Methods and apparatus are disclosed, such as those involving clock and data recovery sampler calibration. One such method includes receiving an electronic data stream by a clock and data recovery (CDR) circuit comprising a data sampler and an edge sampler. The data stream includes data portions and transitioning portions. The method further includes conducting calibration of the CDR circuit. The calibration includes acquiring samples from the transitioning portions of the data stream using the data sampler; and calibrating the data sampler based at least partially on the samples acquired using the data sampler. The method allows one not only to improve performance, but also to improve yield and reduce testing and screening requirements without requiring any additional circuitry to detect the offsets and works with regular input signals.

Clock and data recovery sampler calibration

A method and apparatus are provided for calibrating a multi-stage A/D converter, such as a pipelined A/D converter. The method and apparatus are based on estimating the bounds of histograms of codes from various stages in the A/D converter. Known approaches were effective in calibrating A/D converters but during bound estimation suffered from lock-up conditions from which it could not recover. Embodiments of the present invention describe two mechanisms for recovering from lock-up conditions and a mechanism for fast locking. If neither a gross lock-up condition nor a fine lock-up condition is detected, the estimated bound is modified based on a comparison of a current digital residue with a fast lock value and a bound window. A discontinuity in the transfer characteristic of the A/D converter can then be removed based on the estimated bound.

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Burnaby, Canada

Dragos Cartina