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:
Sep. 21, 1999
Filed:
Oct. 03, 1997
John Edward Hanna, Chandler, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A high precision DAC (10) incorporates a low precision DAC (18) and current sources (15(A)-15(O)) whose full-scale currents are adjusted to match a reference current generated by an analog calibration circuit (28). An additional low precision DAC (20) and another current source (16) are spares that allow periodic calibration of the high precision DAC (10) to occur in the background without taking the high precision DAC (10) off-line or out of service. A thermometer code generated by a thermometer code circuit (12) is used by a thermometer mapper circuit (13) to enable the most recently calibrated current sources to generate currents having the highest probability for use by the high precision DAC (10).