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:
Apr. 20, 2004
Filed:
May. 07, 2002
Applicant:
Inventors:
Ka Y. Leung, Austin, TX (US);
Douglas R. Holberg, Wimberley, TX (US);
Assignee:
Cygnal Integrated Products, Inc., Austin, TX (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03M 1/66 ;
U.S. Cl.
CPC ...
H03M 1/66 ;
Abstract
A digital-to-analog converter having series-connected transistors forming high impedance current sources for respective segmented resistor strings. A series transistor forming a current sink for one resistor string presents a high output impedance by utilizing a negative feedback amplifier. The effects of a headroom resistor and an offset resistor in one resistor string are negated by configuring an output amplifier with appropriate gain resistors. A highly accurate D/A conversion can be achieved by utilizing all resistors of the main and sub-resistor strings with the same value.