Texas Instruments Corporation

Ani Xavier

Jagannathan Venkataraman

Neeraj Shrivastava

Arun Kumar Mohan

Shagun Dusad

Aravind Ganesan

Rishi Soundararajan

Srinivas Kumar Reddy Naru

Viswanathan Nagarajan

Roswald Francis

Sai Aditya Nurani

Rakesh Chikkanayakanahalli Manjunath

Visvesvaraya Pentakota Appala

Sandeep Kesrimal Oswal

Nagalinga Swamy Basayya Aremallapur

Charls Babu

Harshavardhan Adepu

Shyam Subramanian

Aviral Singhal

Abhishek Agrawal

Aditya Kumar

Raviteja Velisetti

Basavaraj G Gorguddi

A circuit includes first, second, third, and fourth transistors, and a capacitor. The first transistor has a first terminal, a second terminal, and a control terminal. The second transistor has a first terminal, second terminal, and a control terminal. The capacitor has a first conductor coupled to the second terminal of the first transistor, and a second conductor coupled to the second terminal of the second transistor. The third transistor has a first terminal coupled to the first terminal of the second transistor, a second terminal, and a control terminal coupled to the control terminal of the first transistor. The fourth transistor has a first terminal coupled to the first terminal of the first transistor, a second terminal coupled to the second terminal of the third transistor, and a control terminal coupled to the control terminal of the second transistor.

Pretap equalizable continuous time linear equalizer

An example system includes: interleaving circuitry including a data input, a plurality of data outputs, and a plurality of clock inputs, the data input coupled to the received data input and each of the plurality of clock inputs coupled to one of the plurality of receiver clock outputs; and handoff circuitry coupled to the interleaving circuitry, the handoff circuitry including: comparison circuitry coupled to the clock generation circuitry and configured to compare the plurality of receiver clocks to the transmission clock; clock configuration circuitry coupled to the comparison circuitry and configured to select one of the plurality of receiver clocks based on the comparison circuitry; and a plurality of flip-flops coupled to the clock configuration circuitry and configured to convert the plurality of data outputs from the plurality of receiver clocks to the transmission clock to generate a plurality of transmission data streams based on the one of the plurality of receiver clocks selected by the clock configuration circuitry.

Methods and apparatus to reduce retimer latency and jitter

A signal transmission system includes an equalization filter configured to filter an input signal based at least in part on a feedback signal, a slicer configured to generate data based on the filtered input signal at a plurality of different phases, a synchronizer configured to compute a phase delay between the input signal at each of the different phases and the data, and a pattern generator configured to generate the feedback signal at a phase adjusted by the phase delay.

Signal transmission system for use with eye diagram monitor

In described examples, a charge pump includes an output, first and second transistors, a control circuit, a multiplexer, and a calibration circuit. The first transistor's drain is coupled to the output. The second transistor's drain is part of a current path separate from a current path that includes the first transistor's drain. The control circuit generates a control signal in response to voltages at the gates of the first and second transistors. First and second inputs of the multiplexer are respectively coupled to sources of the first and second transistors. A control input of the multiplexer is coupled to receive the control signal. A first input of the calibration circuit is coupled to an output of the multiplexer. A second input of the calibration circuit receives a reference voltage. First and second outputs of the calibration circuit are respectively coupled to body terminals of the first and second transistors.

Charge pump with output current adjustment

A receiver circuit comprising an equalizer and a method of correcting offset in the equalizer. In an example, the equalizer includes a plurality of delay stages for sampling and storing a sequence input samples, and a plurality of coefficient gain stages, each coupled to a corresponding delay stage to apply a gain corresponding to a coefficient value. The outputs of the coefficient gain stages are summed to produce a weighted sum for quantization by a slicer. Offset correction circuitry is provided, including memory storing a look-up table (LUT) for each coefficient gain stage, each storing offset correction values corresponding to the available coefficient values for the coefficient gain stage. Addressing circuitry retrieves the offset correction values for the coefficient values currently selected for each gain stage, and applies an offset correction corresponding to the sum of the retrieved offset correction values.

Offset correction in high-speed serial link receivers

A first logic gate has a first input coupled to a first circuit input or a second circuit input, a second input selectively coupled to a third circuit input or a fourth circuit input, and a first output. The first output has a signal with a duty cycle that is a function of a phase difference between a first signal on the first input and a second signal on the second input. A second logic gate has a third input coupled to the third circuit input or the fourth circuit input, a fourth input coupled to the second circuit input or the fourth circuit input, and a second output. The second output has a signal with a duty cycle that is a function of a phase difference between a third signal on the third input and a fourth signal on the fourth input.

Calibration of skew between clock phases

An equalization circuit includes a feed-forward equalization (FFE) circuit and a decision feedback equalization (DFE) circuit. The FFE circuit includes a first FFE tap, a second FFE tap coupled to the first FFE tap, and a variable gain amplifier. The variable gain amplifier includes an input and a programmable capacitor. The input is coupled to the first FFE tap and the second FFE tap. The programmable capacitor is coupled to the input. The DFE circuit includes an input and a DFE tap. The input is coupled to the variable gain amplifier. The DFE tap is coupled to the input of the variable gain amplifier.

Serial receiver equalization circuit

In some examples, a system includes a first transistor comprising a first source terminal coupled to a first input terminal, a first drain terminal coupled to a first top plate sampling capacitor, and a first gate terminal. The system also includes a first input-dependent dual clock boost circuit coupled to the first input terminal via a first boost circuit input and to the first gate terminal via a first boost circuit output. The system further includes a second transistor comprising a second source terminal coupled to a second input terminal, a second drain terminal coupled to a second top plate sampling capacitor, and a second gate terminal. The system also includes a second input-dependent dual clock boost circuit coupled to the second input terminal via a second boost circuit input and to the second gate terminal of the second transistor via a second boost circuit output.

Top plate sampling circuit including input-dependent dual clock boost circuits

In some examples, an amplifier stage includes a voltage-gain amplifier stage and a negative capacitance circuit coupled to the voltage-gain amplifier stage, the negative capacitance circuit comprising a first transistor that provides a first temperature-biased current.

Negative capacitance circuits including temperature-compensation biasings

In some examples, an apparatus includes a plurality of first transistors coupled to a first input terminal and a first output terminal. The apparatus also includes a plurality of second transistors coupled to a second input terminal and a second output terminal. The apparatus further includes a plurality of first dummy transistors coupled to the first input terminal and the second output terminal. The apparatus also includes a plurality of second dummy transistors coupled to the second input terminal and the first output terminal.

Parasitic capacitance cancellation using dummy transistors

In described examples, an analog to digital converter (ADC) includes a flash ADC. The flash ADC generates a flash output in response to an input signal, and an error correction block generates a known pattern. A selector block is coupled to the flash ADC and the error correction block, and generates a plurality of selected signals in response to the flash output and the known pattern. A digital to analog converter (DAC) is coupled to the selector block, and generates a coarse analog signal in response to the plurality of selected signals. A residue amplifier is coupled to the DAC, and generates a residual analog signal in response to the coarse analog signal, the input signal and an analog PRBS (pseudo random binary sequence) signal. A residual ADC generates a residual code in response to the residual analog signal.

Pattern based estimation of errors in ADC

An ADC includes a flash ADC. The flash ADC generates a flash output in response to an input signal, and an error correction block generates a known pattern. A selector block is coupled to the flash ADC and the error correction block, and generates a plurality of selected signals in response to the flash output and the known pattern. A digital to analog converter (DAC) is coupled to the selector block, and generates a coarse analog signal in response to the plurality of selected signals. A residue amplifier is coupled to the DAC, and generates a residual analog signal in response to the coarse analog signal, the input signal and an analog PRBS (pseudo random binary sequence) signal. A residual ADC generates a residual code in response to the residual analog signal.

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Ani Xavier