Digital-to-analog converter (DAC) calibration using error DACs
AssigneeQUALCOMM Incorporated
InventorsZhilong Tang, Dongwon Seo
Life of this patent
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Abstract
Certain aspects of the present disclosure provide a digital-to-analog converter (DAC) system. The DAC system generally includes a plurality of current sources, a plurality of calibration DACs, each coupled to a respective one of the plurality of current sources, a reference current source, and a current mirror having a first branch selectively coupled to the plurality of current sources, wherein a second branch of the current mirror is coupled to the reference current source. The DAC system also includes a first error DAC selectively coupled to the first branch and the second branch of the current mirror, and a second error DAC selectively coupled to the first branch and the second branch of the current mirror.
Claims20
A digital-to-analog converter (DAC) system comprising:
- a plurality of current sources;
- a plurality of calibration DACs, each coupled to a respective one of the plurality of current sources;
- a reference current source;
- a current mirror having a first branch selectively coupled to the plurality of current sources, wherein a second branch of the current mirror is coupled to the reference current source;
- a first error DAC selectively coupled to the first branch and the second branch of the current mirror;
- and
- a second error DAC selectively coupled to the first branch and the second branch of the current mirror.
A method for digital-to-analog conversion, comprising:
- selectively coupling a first branch of a current mirror to a plurality of current sources, wherein a second branch of the current mirror is coupled to a reference current source, and wherein each of a plurality of calibration DACs is coupled to a respective one of the plurality of current sources;
- selectively coupling a first error DAC to the first branch and the second branch of the current mirror;
- and
- selectively coupling a second error DAC to the first branch and the second branch of the current mirror.
An apparatus for wireless communication, comprising:
- a transmit chain;
- a digital-to-analog converter (DAC) coupled to the transmit chain, the DAC having a plurality of current sources configured to generate an analog signal based on a digital input code and provide the analog signal to the transmit chain;
- a DAC calibration circuit coupled to the DAC, the DAC calibration circuit comprising:
- a plurality of calibration DACs, each coupled to a respective one of the plurality of current sources;
- a reference current source;
- a current mirror having a first branch selectively coupled to the plurality of current sources, wherein a second branch of the current mirror is coupled to the reference current source;
- a first error DAC selectively coupled to the first branch and the second branch of the current mirror;
- and
- a second error DAC selectively coupled to the first branch and the second branch of the current mirror.
Dependencies are inferred from the claim text.