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. 03, 2001
Filed:
Sep. 14, 1999
Chia-Yuan Chang, Hsinchu, TW;
Yong-Noen Rao, Taichung, TW;
Industrial Technology Research Institute, Hsinchu Hsien, TW;
Abstract
A method and apparatus for converting digital input signal to analog voltage are disclosed herein. The converting apparatus includes the following devices device. One of the pair of reference voltage selecting means is used to select a first voltage level as a first power source. Similarly, a second voltage level is selected as a second power source. The pair of controlled selectively coupling devices couples the first power source or the second power source as the charge power source responding to voltage level of every bit of the second portion of the digital input signal. The voltage cumulating device is used to generate the analog voltage by alternatively charging and redistributing the output capacitor with the first and the second capacitor. The foregoing method includes the following steps. At first, divide reference voltage levels into a first set and a second set of reference voltage levels. Then select a first and a second voltage level from the first and the second set of reference voltage levels as a first and a second power source respectively according to coding of a first portion of said digital input signal. Sequentially select the first power source or the second power source as a charge power source. The output capacitor is electrically coupled to the first storage capacitor or the second storage capacitor, then voltage on said output capacitor being equal to the analog voltage.