Qualcomm Incorporated

Xiahan Zhou

Haibo Fei

Dongwon Seo

Nitz Saputra

Andrew Weil

Parisa Mahmoudidaryan

Certain aspects of the present disclosure provide a digital-to-analog converter (DAC) circuit. The DAC circuit generally includes: a decoder coupled to an input of the DAC circuit and current-steering cells coupled to an output of the decoder. Outputs of the current-steering cells may be coupled to a positive output node and a negative output node of the DAC circuit. The DAC circuit may also include an offset detection circuit including: a comparator having a first input and a second input selectively coupled to the positive output node and the negative output node; and a digital controller having an input coupled to an output of the comparator and an output coupled to the decoder. In some aspects, the DAC circuit includes one or more calibration DACs coupled to the offset detection circuit.

Current digital-to-analog converter (DAC) with direct-current (DC) offset correction

Certain aspects of the present disclosure generally relate to a digital-to-analog converter (DAC) circuit implemented with a dynamic stacked transistor architecture. The DAC circuit generally includes a first current-steering transistor and a second current-steering transistor. The DAC circuit may also include: a first stacked transistor coupled between the first current-steering transistor and a first output of the DAC circuit; a first switch coupled between a gate of the first stacked transistor and a bias voltage node; a second switch coupled between the gate of the first stacked transistor and a voltage rail; a second stacked transistor coupled between the second current-steering transistor and a second output of the DAC circuit; a third switch coupled between a gate of the second stacked transistor and the bias voltage node; and a fourth switch coupled between the gate of the second stacked transistor and the voltage rail.

Digital-to-analog converter (DAC) with dynamic stacked cascode switches

Methods and apparatus for controlling a power supply voltage for a switch driver in a digital-to-analog converter (DAC). An example DAC generally includes a plurality of DAC cells, each DAC cell comprising a current source, a first switch coupled in series with the current source at a first node, and a switch driver having an output coupled to a control input of the first switch; and calibration circuitry having a first input coupled to a first DAC cell in the plurality of DAC cells and having an output coupled to at least one of the plurality of DAC cells, the calibration circuitry being configured to sense a voltage of the first node in the first DAC cell and to control the power supply voltage for the switch driver in the at least one of the plurality of DAC cells, based on the sensed voltage of the first node.

Digital-to-analog converter (DAC) with adaptive calibration scheme

Methods and apparatus for common-mode current removal in a digital-to-analog converter (DAC). An example DAC circuit generally includes a plurality of current-steering cells, a resistor ladder circuit coupled to the plurality of current-steering cells, a first current sink coupled between a shunt branch of the resistor ladder circuit and a reference potential node for the DAC circuit, and a second current sink coupled between a first output of the DAC circuit and the reference potential node.

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San Diego, CA, United States of America

Xiahan Zhou