Qualcomm Incorporated

Ganesh Saripalli

Dongwon Seo

Shahin Mehdizad Taleie

Tongyu Song

Honghao Ji

Derui Kong

Yang You

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.

Transmit digital to analog converter (DAC) spur attenuation

A circuit for digital-to-analog conversion is described. The circuit includes a digital-to-analog converter (DAC). The DAC includes a double cascaded current source and a differential current-mode switch (DCMS). The circuit further includes a direct current (DC) offset stage. The circuit also includes a load attenuator. The double cascaded current source may be between the DCMS and a rail voltage.

Wideband digital to analog converter with built-in load attenuator

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San Diego, CA, United States of America

Ganesh Saripalli