National Semiconductor Corporation

Texas Instruments Corporation

Yongseon Koh

Jitendra Mohan

Laurence Douglas Lewicki

Amit Rane

Nicolas Nodenot

Benjamin Clyde Buchanan

Roger William Clarke

Luu Thanh Nguyen

Peter Deane

Jeffrey A Babcock

Christopher James Smith

Ken Pham

William Paul Mazotti

Bruce Carlton Roberts

Ramsin Michael Ziazadeh

Jia Liu

Vijaya G Ceekala

John P Briant

Michael R Nelson

Janet E Townsend

Roland Ribeiro

Babak Matinpour

Bumha Lee

Horia Giuroiu

Varadarajan Devnath

Abu-Hena Mostafa Kamal

Manu Basil

Mohan Yang

Quyet Nguyen

A system includes a differential clock source configured to provide a reference clock signal and an inverted version of the reference clock signal. The system also includes a quadrature clock source configured to provide a quadrature clock signal that is phase-shifted relative to the reference clock signal. The system also includes a differential sensing circuit coupled to the differential clock source and the quadrature clock source. The differential sensing circuit is configured to determine skew of the quadrature clock signal based on the reference clock signal, the inverted version of the reference clock signal, and the quadrature clock signal.

Differential sensing circuit for clock skew calibration relative to reference clock

A system includes a pseudo-differential clock path configured to convey a first clock signal and a second clock signal, wherein the second clock signal is inverted relative to the first clock signal. The system also includes a sensing circuit coupled to sensing nodes of the pseudo-differential clock path. The sensing circuit is configured to provide a sense signal based on a comparison of the first clock signal and the second clock signal at the sensing nodes. The system also includes a correction circuit coupled to the sensing circuit and to adjustment nodes of the pseudo-differential clock path. The correction circuit is configured to adjust the first clock signal and the second clock signal using digital-to-analog converters (DACs) and the sense signal.

Duty-cycle calibration based on differential clock sensing

The even order harmonic distortion in a differential circuit is reduced or eliminated by treating the amplitude and phase mismatch sources that cause the distortion as impedance mismatches, and utilizing switched resistor circuitry that adjusts the load resistance to reduce the effects of the amplitude mismatch sources, and switched capacitor circuitry that adds shunt capacitance to reduce the effects of the phase mismatch sources.

Differential analog signal processing stage with reduced even order harmonic distortion

Circuitry for adaptive signal equalizing with coarse and fine boost controls by providing multiple serially coupled stages of parallel controllable DC and AC signal gains with coarse and fine gain controls provided across all stages.

Adaptive signal equalizer with segmented coarse and fine controls

Method and system for adaptive signal equalizing with alternating boost and amplitude controls. In accordance with one exemplary embodiment, data signal boost control is based on measured equalized and sliced data signal energies within a bandwidth disposed about a higher frequency, while sliced data signal amplitude control is based on measured equalized and sliced data signal energies within a bandwidth disposed about a lower frequency.

System and method for providing adaptively equalized data signal with alternately adjusted data signal boost and sliced data signal amplitude

System and method for adaptive signal equalizing in which overlapping data signal equalization paths provide cumulative data signal equalization to provide multiple equalized data signals having different available amounts of equalization. Signal slicing circuitry slices the equalized data signals to provide multiple sliced data signals, from which the sliced data signal selected as an output data signal is dependent upon the data rate of the incoming data signal.

System and method for adaptively equalizing data signals with higher and lower data rates

An analog device under test circuit and a built-in test circuit for testing an AC transfer characteristic of the analog device under test are fabricated on an integrated circuit. The built-in test circuit includes an amplitude detector that detects the amplitude of the output signal of the analog device under test. The test time is reduced by sampling in real-time the DC value corresponding to the amplitude of the analog device under test. An additional reduction in the test time is achieved by using comparators with upper and lower limit reference signals and a pass-fail logic test.

Built-in test circuit for testing AC transfer characteristic of high-speed analog circuit

An electrically floating region is formed in the top surface of a semiconductor wafer to implement a radio frequency (RF) blocking structure. The RF blocking structure lies below the metal pads and traces that carry an RF signal in a metal interconnect structure to substantially reduces the attenuation of the RF signal.

Method of forming a semiconductor die with reduced RF attenuation

An integrated circuit comprises a pin coupled to receive signals from outside the integrated circuit and an input network. The input network equalizes incoming signals by attenuating lower frequency input signals more than higher frequency input signals received at the pin. The input network is configured to generate a DC bias voltage at an output of the input network in response to an AC coupled input signal or a DC coupled input signal received at the pin with a wide common-mode range.

All-pass termination network with equalization and wide common-mode range

The attenuation of an RF signal on a metal trace in a semiconductor die is substantially reduced by utilizing a number of RF blocking structures that lie on the surface of the substrate directly below the metal trace that carries the RF signal. The RF blocking structures include an isolation ring, and one or more doped regions that are formed inside the isolation ring.

Semiconductor die with reduced RF attenuation

A divide-by-N clock frequency divider producing N non-overlapping clocks each with precise 1/N duty ratio is implemented by a counter, a token generator and N-bit shift register. Every N clock cycles, a pulse is generated as a token from a logical combination of signals from the counter. The pulse is passed along a shift register having balanced load capacitances under control of the clock edge, ensuring a precise 1/N duty ratio that is unaffected by load capacitances from the fault state detection and/or reset circuitry. In this manner, a higher operating frequency may be achieved with low power consumption.

Method for generating non-overlapping N-phases of divide-by-N clocks with precise 1/N duty ratio using a shift register

A system and a method are disclosed for providing a constant swing high-gain complementary differential limiting amplifier. High gain for the differential amplifier is created by providing a current to the driving transistors that is a combination of any of (a) constant current, (b) transconductance based current, and (c) temperature compensated based current. A constant differential output swing is created by providing a varying differential current to the output load resistors of the differential amplifier that tracks process and temperature variations within the output load resistors.

System and method for providing a constant swing high-gain complementary differential limiting amplifier

An analog signal gain controller and equalizer with an increased signal bandwidth for reducing intersymbol interference (ISI) within a digital data signal.

Combined analog signal gain controller and equalizer

Concepts for conveniently arranging devices for the transduction of signals to and from voltage and current domains to infrared radiation domains is described. Specifically, optoelectronic components and methods of making the same are described. In one aspect, the optoelectronic component includes a base substrate having a pair of angled (or substantially perpendicular) faces with electrical traces extending therebetween. A semiconductor chip assembly is mounted on the first face of the base substrate and a photonic device is mounted on the second face. Both the semiconductor chip assembly and the photonic device are electrically connected to traces on the base substrate. The semiconductor chip assembly is generally arranged to be electrically connected to external devices. The photonic devices are generally arranged to optically communicate with one or more optical fibers. The described structure may be used with a wide variety of photonic devices. In some embodiments the base substrate is formed from a ceramic material having the electrical traces formed thereon. In other implementations the substrate includes a backing block having a flexible printed circuit substrate adhered thereto.

Optical sub-assembly for opto-electronic modules

A circuit and method for generating quadrature signals with a deterministic phase relationship. Between two inductive-capacitive (LC) based quadrature voltage controlled oscillators (VCO), phase shift circuitry is interposed such that the individual LC VCO circuits produce signals with corresponding phase delays which ensure that the desired lead or lag phase relationship between the quadrature signals is achieved.

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Palo Alto, CA, United States of America

Yongseon Koh