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. 16, 2001
Filed:
Oct. 08, 1999
Cynthia Blair, Morgan Hill, CA (US);
Henrik Sjoden, Morgan Hill, CA (US);
Ericsson Inc., Research Triangle Park, NC (US);
Abstract
A circuit and method are disclosed for biasing a power transistor to offset unwanted variations in the operating characteristics thereof. The circuit includes a correction transistor having the same device structure as the structure of the power transistor. In addition, one or more dimensions of the correction transistor is scaled relative to corresponding dimensions of the power transistor. The correction transistor is biased so that the ratio of drain currents of the correction transistor and the power transistor is the same as the size ratio thereof. In this way, the output signal of the correction transistor is based upon an unwanted variation in the operating characteristics of the power transistor. The output terminal of the correction transistor is amplified and coupled to the control terminal of the power transistor so that the bias signal applied to the control terminal thereof offsets the unwanted variation in the operating characteristics of the power transistor.