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:
Oct. 29, 2002
Kern W. Wong, Sunnyvale, CA (US);
Jane Xin-Leblanc, Sunnyvale, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A band-gap reference circuit comprising a first current source for generating a first reference current and a first circuit branch for receiving part of the first reference current. The first circuit branch comprises a first resistor having a positive temperature coefficient in series with a base-emitter junction of a first PNP diode having a negative temperature coefficient. An emitter current of the first PNP diode develops a first combined voltage across the first resistor and the base-emitter junction. A comparison circuit compares the first combined voltage to a base-emitter voltage of a second PNP diode and adjusts a band-gap reference voltage. A correction current generating circuit injects a correction current into an emitter of the second PNP diode that at least partially offsets a non-linear drop-off in the band-gap reference voltage caused by the second PNP diode as temperature increases.