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:
Aug. 15, 1989
Filed:
Sep. 22, 1988
Ricky F Bitting, Fort Collins, CO (US);
NCR Corporation, Dayton, OH (US);
Abstract
A bandgap voltage reference start-up circuit configured to initiate bandgap reference operation over an extended temperature range while being relatively insensitive to the effects of fabrication process variables. The circuit as preferably implemented includes a differential amplifier in the bandgap voltage reference stage which controls the source of current to contrasted bipolar devices situated in parallel paths. A comparator monitors the activities of the current source drive signal and compares that to an internally generated reference, which reference is configured to the matched in temperature and process variable effect the corresponding bandgap reference bipolar device and the current source device. During start-up the comparator initiates an injection of current into one bipolar device of the bandgap reference circuit to drive the bandgap loop into the appropriate of two potential operating states. The preferred embodiment also includes a power-down mode capability.