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:
Oct. 02, 1990
Filed:
Oct. 27, 1989
Randall C Gray, Tempe, AZ (US);
Arthur Edwards, Hoffman Estates, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A digital to analog converter circuit produces an output voltage which includes a small error voltage floating on a larger direct current voltage component. The circuit includes a controlled current supply coupled to the emitter of an NPN transistor to which the direct current voltage component is supplied to the base thereof. The error voltage is generated by modulating the current through the transistor by controlling the current supply, independent of the voltage component supplied to its base, such that the output voltage occurring at the emitter of the transistor is a function of the difference between the direct current component and the natural log of the modulated emitter current.