Qualcomm Incorporated

Honghao Ji

Dongwon Seo

Behnam Sedighi

Lei Sun

Shahin Mehdizad Taleie

Ashok Swaminathan

Nitz Saputra

Andrew Weil

Tongyu Song

Sang Min Lee

Negar Rashidi

Yongjian Tang

Jaswinder Singh

Xilin Liu

Siyu Yang

Ganesh Saripalli

Dan Yuan

Eunyung Sung

Sudharsan Kanagaraj

Vinay Kundur

Yang You

Certain aspects of the present disclosure are directed towards an interleaved sampling circuit. The interleaved sampling circuit generally includes: a clock generator having an input coupled to a main clock node and having a plurality of non-overlapping clock output nodes; and a plurality of sampling circuits, each of the plurality of sampling circuits having a first clock input coupled to a respective one of the non-overlapping clock output nodes and a second clock input coupled to the main clock node.

Interleaved sampling circuit

A system includes a bootstrap circuit having an input and an output. The bootstrap circuit includes a boost capacitor having a first terminal and a second terminal, a first transistor coupled between the first terminal of the boost capacitor and the output of the bootstrap circuit, a second transistor, and a third transistor, wherein the second transistor and the third transistor are coupled in series between a gate of the first transistor and the second terminal of the boost capacitor. The system also includes a switch transistor, wherein a gate of the switch transistor is coupled to the output of the bootstrap circuit, and a terminal of the switch transistor is coupled to the input of the bootstrap circuit.

Non-overlapping generation technique for bootstrap switches

Certain aspects of the present disclosure provide a successive approximation register (SAR) analog-to-digital converter (ADC) implemented with a digital filter for noise shaping. For example, certain aspects provide a circuit for analog-to-digital conversion having: a first digital-to-analog converter (DAC) having an output coupled to a sampling node; a comparator having an input coupled to the sampling node; SAR logic having an input coupled to an output of the comparator and at least one output coupled to an input of the first DAC; a quantizer configured to generate a first digital signal representing a voltage at the sampling node; a digital filter configured to apply a filter to the first digital signal; and a second DAC configured to generate an analog signal representing the filtered first digital signal and provide the analog signal to the sampling node.

Successive approximation register (SAR) analog-to-digital converter (ADC) with noise-shaping property

A current digital-to-analog converter includes a binary current-generating section configured to generate a binary-weighted current based on a first set of control signals; a unary current-generating section configured to generate a unary-weighted current based on a second set of control signals; and a current combining circuit configured to add or subtract a reference current and a current generated by a current source of the unary current-generating section using the binary-weighted current.

Apparatus and method for measuring current source mismatches in current-steering DAC by re-using R2R network

An interleaved digital-to-analog converter (DAC) system may include a first sub-DAC and a second sub-DAC and may be configured to provide both a converter output signal and a calibration output signal. The converter output signal may be provided by adding the first sub-DAC output signal and the second sub-DAC output signal. The calibration output signal may be provided by subtracting one of the first and second sub-DAC output signals from the other. The calibration output signal may be used as feedback to adjust the phase of one of the sub-DACs relative to the other, to promote phase matching their output signals.

Image calibration for time-interleaved digital-to-analog converter

A calibrating digital to analog converter (calDAC) architecture uses a low voltage memory to store the digital inputs of calDACs. The calDAC architecture includes a low voltage domain and a high voltage domain coupled to the low voltage domain. The low voltage domain includes a calDAC memory and a finite state machine (FSM). The high voltage domain includes a calDAC core, an interface circuit, and a bias control circuit coupled to the interface circuit. The interface circuit may be provided between the calDAC core and the low voltage domain. The bias control circuit is coupled to the interface circuit to generate a bias voltage for the interface circuit to drive switch transistors of the calDAC core.

Low voltage input calibrating digital to analog converter

A reverse current protection (RCP) circuit is provided that includes an RCP switch coupled between a power supply rail and a buffer power supply node. A control circuit powered by a buffer supply voltage on the buffer power supply node controls the RCP switch to open in response to a discharge of a power supply voltage carried on the power supply rail.

Self-sensing reverse current protection switch

A method and apparatus for attenuating transmit digital to analog converter (DAC) spurs is provided. The method begins when a reference voltage is injected into an amplifier. Next, an output of the ground low drop-out regulator is measured and is them compared with the reference voltage. The output of the amplifier is then adjusted based on the results of the comparison. If the reference voltage is higher then the output of the ground low drop-out regulator the output of the amplifier is adjusted to ground. If the reference voltage is lower than the output of the ground low drop-out regulator then the output of the amplifier is adjusted to match the reference voltage.

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San Diego, CA, United States of America

Honghao Ji