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:
Jul. 30, 2002
Filed:
Aug. 18, 2000
Jay Friedman, Felton, CA (US);
Ion E. Opris, Sunnyvale, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
In a bandgap voltage reference circuit in accordance with the present invention, the different-sized emitters of the two bipolar devices of a &Dgr;V stage return to ground (or other bias voltage) through separate resistors. The V term of the reference device is supplied by a V current source through a third resistor. The proportional-to-absolute-temperature (PTAT) term of the reference occurs as the difference of base-emitter voltages &Dgr;V between the larger and smaller emitters. An output voltage V multiplier resistor feeds to the larger emitter through an inverting amplifier. In one embodiment of the invention, the output voltage V trim at one temperature is obtained by trimming the base-emitter resistor of the “small emitter” device to compensate for the V process variation.