Qualcomm Incorporated

Microchip Technology Inc.

Rambus Inc.

Omid Rajaee

Dinesh Jagannath Alladi

Liang Dai

Rahim Bagheri

Jun Wang

Ganesh Kiran

Mahdi Bagheri

Mohammad Mehrjoo

Changsok Han

Edwin Chiem

Saeed Pourbagheri

Yan Wang

Kambiz Kaviani

Elias Dagher

Seyed Arash Mirhaj

Ting Wu

Kentaro Yamamoto

Yuhua Guo

Wei Zheng

Jason Chia-Jen Wei

Li Lu

Delta-sigma modulation utilizing continuous-time input and discrete-time loop filter. An apparatus includes an input circuit, a switched-capacitor, an integrator, a quantizer and a feedback loop. The input circuit receives an analog signal and produce an analog input signal, the input circuit comprising a resistor-capacitor (RC) integrator. The switched-capacitor samples the analog input signal and produce a discrete-time, sampled input signal. The integrator processes the discrete-time, sampled input signal. The quantizer converts an output of the integrator to a digital signal. The feedback loop provides the digital signal to respective inputs of the RC integrator and the integrator.

ΔΣmodulation utilizing continuous-time input and discrete-time loop filter

Various embodiments relate to delta-sigma loop filters with input feedforward. A delta-sigma loop filter may include a first integrator and a quantizer having an input coupled to an output of the first integrator. The delta-sigma loop filter may further include a first summing node having an output coupled to an input of the first integrator. Further, the delta-sigma loop filter may include a feedforward path from an input of the delta-sigma loop filter to a first input of the first summing node. The delta-sigma loop filter may also include a first feedback path from an output of the quantizer to a second input of the first summing node.

Delta-sigma loop filters with input feedforward

Various embodiments relate to an analog-to-digital converter (ADC). The ADC may include a first channel including a first delta-sigma loop filter and a second channel including a second delta-sigma loop filter. Each of the first delta-sigma loop filter and the second delta-sigma loop filter may include a first integrator and a quantizer having an input coupled to an output of the first integrator. Each of the first delta-sigma loop filter and the second delta-sigma loop filter may also include a first summing node having an output coupled to an input of the first integrator, and a feedforward path from an input of the delta sigma loop filter to a first input of the first summing node. Further, each of the first delta-sigma loop filter and the second delta-sigma loop filter may include a first feedback path from an output of the quantizer to a second input of the first summing node.

Programmable receivers including a delta-sigma modulator

A continuous-time analog-to-digital converter (ADC) includes a plurality of integrators selectively coupled in series. The ADC may further include a quantizer with excess loop delay (ELD) compensation. The quantizer may be coupled in series to a least one integrator. The ELD compensation may be programmable based on a transfer function of the ADC. The ADC may further include parallel digital-to-analog converters (DACs). Each DAC may have an input coupled to an output of the quantizer, and an output coupled to an input of a corresponding integrator. The ADC may further include a bypass path coupled to an input or output of one of the integrators. The bypass path may be configured to selectively bypass one or more of the integrators to change the transfer function of the ADC.

Continuous-time analog-to-digital converter

Certain aspects of the present disclosure provide apparatus and techniques for analog-to-digital conversion using a time-to-digital converter (TDC). For example, certain aspects provide a quantizer using a TDC. The quantizer may include at least one first capacitive element and a set of switches configured to selectively couple a first terminal and a second terminal of the at least one first capacitive element to at least one input voltage source. The TDC may also include a reference voltage source, at least one switch coupled between the second terminal of the at least one first capacitive element and an output of the reference voltage source, a current source selectively coupled to the first terminal of the at least one first capacitive element, and a voltage sense circuit coupled to the first terminal of the at least one first capacitive element.

Time-to-digital converter (TDC)-based quantizer

Certain aspects of the present disclosure provide a segmented successive approximation register (SAR) analog-to-digital converter (ADC). One example ADC generally includes a plurality of SAR ADC circuits each associated with a different voltage range segment of a voltage range for the ADC. Each SAR ADC circuit is configured to receive an analog signal input to the ADC and to output a digital signal based on the analog signal, the digital signal being representative of a voltage level of the analog signal when the voltage level of the analog signal is within the segment associated with the SAR ADC circuit. In certain aspects, the SAR ADC may include logic configured to control a digital output of the ADC based on one or more of the digital signals representative of the voltage level of the analog signal output by one or more of the plurality of SAR ADC circuits.

Segmented successive approximation register (SAR) analog-to-digital converter (ADC) with reduced conversion time

Certain aspects of the present disclosure provide a delta-sigma modulator (DSM) using time-interleaved (TI) successive approximation register (SAR) analog-to-digital converters (ADCs). For example, two SAR ADCs may be configured to alternately sample and process an input signal and provide a feedback signal for the DSM using excess loop delay (ELD). In other aspects, the DSM may be implemented using a two-step SAR quantizer. For example, a first SAR ADC may sample an input signal to generate a most-significant bit (MSB) portion of an output of the DSM, while the second SAR ADC may subsequently sample a residue from the first SAR ADC conversion and generate a least-significant bit (LSB) portion of the output of the DSM. With these techniques, higher bandwidths may be obtained in high accuracy delta-sigma ADCs without using increased sampling rates.

Delta-sigma analog-to-digital converter (ADC) with time-interleaved (TI) or two-step successive approximation register (SAR) quantizer

An analog-to-digital converter includes: a first input terminal to receive a first input signal; a second input terminal to receive a second input signal; a noise shaping module configured to compare the first input signal to the second input signal received, and to output a digital output signal and a residue signal in a first phase of a noise shaping operation; and a storage module configured to store the residue signal during the first phase of the noise shaping operation, the storage module configured to receive an analog input signal and remove the residue signal from the analog input signal in a second phase of the noise shaping operation to output a new first input signal to the noise shaping module.

Noise shaping successive approximation register analog-to-digital converter

Certain aspects of the present disclosure provide a voltage level shifting circuit employing a low latency, AC-coupled voltage boost circuit, as well as other circuits and apparatus incorporating such a level shifting circuit. Such level shifting circuits provide significantly lower latency compared to conventional level shifters (e.g., latency reduced by at least a factor of two). Offering consistent latency over the simulation corners, level shifting circuits described herein also provide significantly lower power consumption and reduced duty cycle distortion compared to conventional level shifters.

Voltage level shifter with a low-latency voltage boost circuit

The present disclosure includes circuits and methods for latching signals. In one embodiment, two inverters are configured back to back to latch a signal. Each inverter includes a capacitor configured between control terminals of inverter transistors. In one embodiment, the circuit is part of a comparator. First and second voltages are received on control terminals of differential transistors, and a differential output signal is coupled to two back to back inverters. In one embodiment, a circuit is disabled and a voltage on a control terminal of a transistor in an inverter is set below a reference, such as a power supply, to increase the speed of the circuit.

Latch comparator circuits and methods

Exemplary embodiments are directed to systems, devices, and methods for enhancing an amplifier. An amplifier may include a first cascode circuit including a first transistor and a second transistor. The amplifier may include a second cascode circuit coupled to a differential output and including a first pair of transistors including a first transistor and a second transistor and a second pair of transistors including a third transistor and a fourth transistor. Further, the amplifier may include a differential input including a first transistor coupled to each of the first transistor of the first cascode circuit and the first and second transistors of the second cascode circuit, the differential input further including a second transistor coupled to each of the second transistor of the first cascode circuit and the third and fourth transistors of the second cascode circuit.

Folded cascode amplifier

Exemplary embodiments are directed to systems, devices, and methods for enhancing a telescopic amplifier. An amplifier may include a differential pair of input transistors including at least one transistor configured to receive a first input and at least one other transistor configured to receive a second input. The amplifier may further include a cascode circuit including a first pair of transistors coupled to the at least one transistor of the differential pair to form a first plurality of current paths configured to generate a first output. The cascode circuit may also include a second pair of transistors coupled to the at least one other transistor of the differential pair to form a second plurality of currents paths configured to generate a second output.

Hybrid amplifier

A low distortion feed forward delta sigma modulator includes a first adder configured to receive a feedback signal and an input signal. The modulator also includes a first integrator configured to receive an output from the first adder, and a second integrator configured to receive an output from the first integrator. The modulator further includes a second adder configured to receive a second integrated path from the second integrator, a first integrating path from the first integrator and a first summing path from the input signal. The modulator also has a last integrator configured to receive an output from the second adder.

Low distortion feed-forward delta-sigma modulator

A linear equalizer (LEQ) includes a first transconductance device coupled to an input node of the LEQ and a second transconductance device AC coupled to the input node of the LEQ to increase a gain of the LEQ for data signals above a predetermined frequency. The first transconductance device and the second transconductance device are of complimentary types. A bimodal LEQ includes inputs to control operation of the bimodal LEQ in a current mode or a voltage mode. The bimodal LEQ includes first and second transconductance devices. One of the first and second transconductance devices is AC coupled to an input node to increase the gain for data signals above a predetermined frequency.

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San Diego, CA, United States of America

Omid Rajaee