The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 28, 2014
Filed:
Mar. 15, 2013
Qualcomm Incorporated, San Diego, CA (US);
Tongyu Song, San Diego, CA (US);
Sang Min Lee, San Diego, CA (US);
Derui Kong, San Diego, CA (US);
Dongwon Seo, San Diego, CA (US);
QUALCOMM Incorporated, San Diego, CA (US);
Abstract
A digital-to-analog converter (DAC) includes, in part, a multitude of input stages that supply currents to a pair of current summing nodes in response to a digital signal, and an impedance attenuator coupled between the current summing nodes and the output of the DAC. The impedance attenuator is adapted, among other function, to increase the range of impedances of the output load, to account for changes in the output load impedance due to variations in the process, voltage and temperature, and to decouple the impedances seen by the summing nodes from the load impedance. The impedance attenuator further includes a differential-input, differential-output amplifier with programmable common-mode gain bandwidth to control the harmonic distortion of the amplifier. The impedance attenuator optionally includes a pair of cross-coupled capacitors to control the harmonic distortion of the amplifier.