Abstract:
A compensation circuit and method for reducing ISI products within an electrical data signal corresponding to a detected data signal received via a signal transmission medium introduces distinct compensation effects for individual ISI products within the electrical data signal. Distinct data signal components within the detected data signal and corresponding to such ISI products can be selectively and individually compensated, thereby producing a compensated data signal in which each selected one of such individual data signal components is substantially removed. Individual data signal components or selected combinations of data signal components can be compensated as desired.
Abstract:
An apparatus and method for adaptively introducing a compensating signal latency related to a signal latency of a data symbol decision circuit. Adaptive timing control circuitry, including an interpolating mixer implemented as a tapped delay line with correlated tap coefficients, introduces a latency adaptively and substantially matching the latency of the data decision circuit for use within an adaptive equalizer, thereby minimizing the mean-squared error of such decision circuit. This adaptive latency is used in generating the feedback error signal which, in turn, can be used by the feedforward equalizer for dynamically adjusting its adaptive filter tap coefficients.
Abstract:
A compensation circuit and method for reducing ISI products within an electrical data signal corresponding to a detected data signal received via a signal transmission medium introduces distinct compensation effects for individual ISI products within the electrical data signal. Distinct data signal components within the detected data signal and corresponding to such ISI products can be selectively and individually compensated, thereby producing a compensated data signal in which each selected one of such individual data signal components is substantially removed. Individual data signal components or selected combinations of data signal components can be compensated as desired.
Abstract:
A data signal peak error detector for monitoring and detecting undesired shifts in the peak levels of a multilevel data signal, such as an MLT3 Ethernet signal. A signal slicing circuit generates two signals: a data peak detection signal identifies occurrences of data signal peaks and is asserted when the input data signal level has transitioned beyond a value which is intermediate to preceding intermediate and peak (e.g., positive or negative) signal levels; and a data peak error signal identifies occurrences of data signal peak errors and is asserted when the input data signal level has transitioned beyond a value which corresponds to a preceding peak signal level. Assertion of the data peak detection signal initiates a count sequence by a counter. The count sequence is decoded to produce one or more signal pulses, each of which is provided at a respective time after assertion of the first data peak signal and identifies a valid state of the data peak error signal.
Abstract:
A high speed data receiver for recovering binary or MLT3 encoded data which has been received via a cable. An adaptive equalizer provides signal gain which increases with frequency and adapts according to the length of the cable. Control over such adaptive equalizing is achieved by monitoring the peak-to-peak amplitude, amplitude peaks and differences between amplitude peaks of the equalized data signal during defined time intervals. Baseline restoration and dynamic data slicing are also provided.
Abstract:
A digital-to-analog converter for converting a multiple bit digital input signal into multiple representative analog output signals includes a pulse density modulator, a logic controller, signal selection logic circuits and resistive-capacitive lowpass output filters. The pulse density modulator receives the N-M least significant bits of an N-bit digital input signal and in accordance therewith generates a pulse density modulated digital signal with a pulse density corresponding to a digital count of such N-M least significant bits. The logic controller receives the M most significant bits of the N-bit digital input signal and in accordance therewith generates multiple pairs of digital control signals. Each of the signal selection logic circuits receives the pulse density modulated digital signal and a respective pair of the digital control signals and in accordance therewith provides a respective one of a number of digital output signals. Together, each pair of digital control signals determines whether one of them or the pulse density modulated digital signal is provided as the respective digital output signal. The output filters lowpass filter the digital output signals to convert them to analog signals. The resulting analog signals represent a digital count of the original digital signal bits.
Abstract:
An adaptive signal equalizer with a feedforward filter in which the feedback error signal and corresponding incoming data signal are dynamically aligned in time using signal interpolation, and further, to control the precursor/postcursor filter taps configuration, thereby producing more adaptive filter tap coefficient signals for significantly improved and robust signal equalization.
Abstract:
Systems and methods provide automatic gain control, such as by employing analog and digital techniques. For example, overall gain may be controlled through coarse and fine control signals provided to gain stages, with the overall gain monitored via a power detector circuit.
Abstract:
An inductor for an integrated circuit made of a plurality of stacked, electrically coupled, metal layers. Each metal layer includes an inductor formed of a spiral pattern, which except for the top and bottom inductors, are electrically coupled to the spiral inductor formed on the metal layer above and below with an electrical path or via formed between each metal layer. The top and bottom inductors are electrically coupled to the inductor directly below and above, respectively.
Abstract:
A digital signal error detection circuit and method for identifying interruptions in respective occurrences of opposing signal states of an equalized digital data signal. Signal level status signals are monitored during a specified monitoring time period to determine whether the data signal being monitored contains at least one positive data pulse and at least one negative data pulse. If this condition is not met, then an error signal is generated for use in correcting the equalization of the original data signal.