Lsi Logic Corporation

Lsi Corporation

Avago Technologies General IP (singapore) Pte. Ltd.

Brett D Hardy

Alan S Fiedler

Lane Allen Smith

Vladimir Sindalovsky

Weiwei Mao

Mohammad Shafiul Mobin

Michael O Jenkins

Christopher John Abel

Prashant K Singh

Jeffrey S Kueng

Donald C Grillo

Ye Liu

Francois Ducaroir

Joseph Anidjar

John Lynn McNitt

Andrew Cable

Philip N Jenkins

Michael Okronglis

An apparatus for powering an electrical circuit includes a first voltage input configured to receive power from a first voltage source, a second voltage input configured to receive power from a second voltage source, wherein the second voltage source has a lower voltage than the first voltage source, a voltage regulator connected to the first voltage input, and a voltage output configured to switchably receive power from the first voltage input through the voltage regulator or from the second voltage input.

Transmitter power supply with selective source and regulation

Described embodiments provide for, in a SerDes device, an adaptation process that adjusts data path gain through programmable-bias based on process, voltage, temperature (PVT) and data rate changes. Such adaptation process extends bias current dynamic range, and low frequency gain can be programmed to a desired target range of values for a given variable gain amplifier (VGA) setting at any PVT and data rate corner. A receive (RX) data path structure auto-adapts data path gain through programmable bias based on sensed PVT and data rate changes. The low frequency attenuation/gain range is extended, and can be programmed to a desirable targeted range by a SerDes device RX adaptive process for a given VGA and linear equalizer (LEQ) setting at any given PVT and data rate condition.

Data rate and PVT adaptation with programmable bias control in a SerDes receiver

A tap coefficient control circuit and a method for controlling a tap coefficient for a decision feedback equalizer are disclosed. The method includes adjusting a correction voltage applied to the tap coefficient based on a first tap quantization and detecting a decision feedback equalizer tap convergence. After the decision feedback equalizer tap convergence is detected, the method adjusts the correction voltage applied to the tap coefficient based on a second tap quantization, wherein the second tap quantization is different from the first tap quantization.

Pre and post-acquisition tap quantization adjustment in decision feedback equalizer

In described embodiments, a VCO based CDR for a SerDes device includes a phase detector, a VCO responsive to a first control signal and a second control signal and generating an output signal, a frequency calibration module configured to calibrate the frequency of the output signal by performing a coarse calibration and a subsequent fine calibration, a gear shifting control module controlling a gain change of the first and second control signals in time, and a look-up table created by fine calibration values generated from the frequency calibration module, wherein the programmed variable gain of the gear shifting control module is calculated by a calculation circuit employing the fine calibration values stored in the look-up table, the calculation of the calculation circuit adjusts gear shifting down, and adjusts a gear shifting gain, and adjusting an overall CDR gain over a VCO control curve.

Serializer-deserializer clock and data recovery gain adjustment

In described embodiments, a receiver includes a clock and data recovery (CDR) circuit with a voltage control oscillator (VCO) having proportional and integral loop control, and a Lock to Reference (L2R) mode circuit using Phase and Frequency Detector (PFD) control of the VCO during the absence of input data to the CDR. A regular CDR second order loop incorporating PFD control of the VCO during the absence of input data to the CDR achieves relatively rapid lock to reference when compared to counter-based lock to reference mode of operation.

CDR with digitally controlled lock to reference

Methods and apparatus are provided for adaptation of continuous time-decision feedback equalizers with programmable adaptation patterns. A continuous time-decision feedback equalizer is adapted by obtaining at least one programmable signature pattern that triggers adaptation of one or more of a pole and a gain of the continuous time-decision feedback equalizer; detecting the at least one programmable signature pattern in an incoming signal; and adapting one or more of the pole and the gain of the continuous time-decision feedback equalizer when the at least one programmable signature pattern is detected in the incoming signal. The programmable signature pattern can be selected to ensure an unambiguous direction of change in an error sample when a corresponding one of the pole and the gain are modified.

Methods and apparatus for adaptation of continuous time-decision feedback equalizers with programmable adaptation patterns

A method is provided for transmitting serial data. The method includes receiving successive transmit data words, wherein each transmit data word has a plurality of bits. Each of the plurality of bits in each transmit data word is multiplied into a multiple number of adjacent bits to form an expanded data word. Each of the expanded data words is serialized to form a serial data word stream, which is transmitted.

Serial data transmitter with bit doubling

An inductor-capacitor voltage controlled oscillator is implemented using an active inductor. The active inductor may use bipolar technology or CMOS technology. The VCO with an active inductor offers a more compact design and is useable with flip chip technology. The active inductor may be implemented in bipolar junction or complementary metal oxide semiconductor technology. The configuration of the voltage controlled oscillator with an active inductor of the present invention is fully differential and fully symmetric.

Widely tuneable and fully differential LC oscillator utilizing an active inductor

An over-voltage protected integrated circuit is provided, which includes a discharge node, an input-output pad, a signal trace, which is coupled to the input-output pad, and a pair of back-to-back diodes, which is coupled between the first signal trace and the discharge node.

ESD protection circuit for low amplitude signals

A serial data communication receiver includes a serial data input, first and second equalizers, first and second capture latch circuits, and an equalization control circuit. The first and second equalizers are coupled to the serial data input and have first and second equalized serial data outputs, respectively. Each equalizer has a frequency response that is variable over a range of frequency response settings. The first and second capture latch circuits are coupled to the first and second equalized serial data outputs, respectively, in a phase-locked loop and have first and second recovered data outputs, respectively. The equalization control circuit measures a data eye size of the second equalized serial data output over the range of frequency response settings of the second equalizer and sets the frequency response of the first equalizer to one of the frequency response settings based on the measured data eye sizes.

Serial data communication receiver having adaptive equalization

A termination impedance in a semiconductor circuit is trimmed to fall within a desired range by a trimming circuit such that the amount of variation in the termination impedance is less than the variation in the sheet rho (resistivity) of the semiconductor. An external reference resistor causes a reference current to flow in multiple branches of a current mirror circuit. One branch of the current mirror circuit has a resistance less than the reference resistor, another has a resistance approximately equal to the reference resistor, and another has resistance greater than the reference resistor. Variation in the sheet rho results voltage drops across the resistor in variation in the resistor values. A logic circuit detects the variations, and encodes a control signal. The control signal is received by a variable termination circuit that switches parallel resistance branches in or out of the termination impedance circuit such that an effective termination impedance is selected based upon the control signal. The resulting termination impedance is thereby maintained within a higher tolerance range than the variation in the termination impedance that would otherwise result from sheet rho variation. 37 CFR 1.72( ).

Termination impedance trimming circuit

A data serializer includes a differential output stage. The differential output stage has n pairs of first and second control inputs, wherein each pair of control inputs corresponds to one of n data inputs. Each pair of first and second control inputs is driven by first and second logic AND circuits having p-channel output drive transistors.

Low-power data serializer

A differential output buffer includes first and second complementary data inputs, an idle input, and a differential output stage having first and second output stage control inputs and first and second differential data outputs. First and second push-pull circuits charge one of the first and second output stage control inputs toward a logic high voltage and discharge the other of the first and second output stage control inputs toward a logic low voltage based on relative logic states of the first and second data inputs. A logic low voltage supply generator is coupled to the idle input and the logic low voltage supply terminal for setting the logic low voltage as a function of the idle input.

Reduced-swing differential output buffer with idle function

An analog-to-digital (A/D) converter for converting an analog signal into a digital signal includes a first resistor ladder coupled between a first reference voltage and a second reference voltage. The A/D converter also includes a second resistor ladder that matches the first resistor ladder and that has a first end and a second end coupled to an analog signal source. The first resistor ladder and the second resistor ladder are coupled to at least two comparators with each comparator having a reference input and an analog input. The impedance at each reference input due to the first resistor ladder matches the impedance at each corresponding analog input due to the second resistor ladder.

Source impedance matching in an analog-to-digital converter

An A/D converter has an auto-zeroed latching comparator with an input offset voltage. The latching comparator is repetitively switched between an offset adjustment mode and a conversion mode. When the comparator is in the offset adjustment mode, the comparator compares the reference voltage to itself and generates an offset measurement output based on the comparison. A feedback circuit adjusts the input offset voltage based on the offset measurement output. When the comparator is in the conversion mode, the comparator compares the input signal to the reference voltage and generates the digital output signal based on the comparison.

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Edina, MN, United States of America

Brett D Hardy