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. 15, 1997
Filed:
Sep. 28, 1995
Robert Alan Neidorff, Bedford, NH (US);
Unitrode Corporation, Merrimack, NH (US);
Abstract
A multi-stage digital to analog converter with increased speed and enhanced accuracy. Multiple resistor ladders are interconnected through switches with the first resistor ladder converting the most significant bits and successive ladders converting lesser significant bits. The resistance values of the resistors of each ladder are greater than those of the preceding ladders in order to minimize inaccuracies due to loading. In one embodiment, the last resistor ladder, processing the least significant bits of the digital word to be converted, is a binary weighted resistor divider. A monolithic fabrication technique includes a common resistor biasing scheme to switch the voltage across parasitic capacitances associated with the resistors in each ladder in common mode, thereby increasing the converter speed.