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:
Nov. 21, 2000
Filed:
Aug. 28, 1998
Bruce W McNeill, Allentown, PA (US);
Robert W Walden, Bethlehem, PA (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A bandgap voltage reference circuit for 0.35-.mu.m, 3-volt CMOS technology operates in an essentially temperature independent manner and having low supply voltages. The bandgap voltage reference circuit incorporates two operational amplifiers. One operational amplifier biases bipolar devices of the circuit and generates a PTAT voltage across a resistor, and the other operational amplifier buffers a voltage related to the PTAT voltage and a voltage across one bipolar device to generate the bandgap voltage reference. In one embodiment, the circuit includes a start-up circuit to ensure a stable and desired start-up state. A current bias may also be provided. The bandgap voltage reference of the second operational amplifier may also provide a regulated supply for the first stage of the circuit. The second operational amplifier also provides a buffered output to a resistor divider circuit to supply a voltage divider to generate voltages below the 1.24-volt bandgap voltage. The bandgap voltage reference circuit includes two versions, one which is optimized for a low supply voltage potential V.sub.DD of approximately 1.8 volts and the other for a standard supply voltage V.sub.DD of approximately 2.4 volts.