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:
Jul. 19, 2011
Filed:
Oct. 01, 2009
Tai-cheng Lee, Taipei, TW;
Cheng-hsiao Lin, Taipei, TW;
Tai-Cheng Lee, Taipei, TW;
Cheng-Hsiao Lin, Taipei, TW;
National Taiwan University, Taipei, TW;
Abstract
The digital-to-analog converter in accordance with the present invention comprises an R-2R transistor-only ladder converter and a digital controller. The controller connects to the R-2R transistor-only ladder converter and comprises at least one regulating transistor and at least one shifting transistor. The at least one regulating transistor has an aspect ratio of k(W/L). The at least one shifting transistor has an aspect ratio of k(W/L). Setting the aspect ratios k(W/L) and k(W/L) of the shifting and regulating transistors adjusts a linear output current waveform to a non-linear waveform. The method to output a non-linear current comprises acts of determining an optimum non-linear output current, dividing a linear output current into multiple sections, determining slopes of the waveform of the output current, adding a controller corresponding to an R-2R transistor-only ladder converter, setting aspect ratios k(W/L) of regulating transistors and setting an aspect ratios k(W/L) of shifting transistors.