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:
Sep. 09, 1997
Filed:
Aug. 24, 1995
David F Mietus, Phoenix, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A method for generating a programmable bandgap output reference voltage (V.sub.REF31) and a voltage reference circuit (31) have been provided. The voltage reference circuit (31) includes a pair of bipolar transistors (33, 34), a resistor (36), an operational amplifier (32) and a plurality of field effect transistors (38, 39, 41) configured to generate a current (I.sub.1 ') having a positive temperature coefficient. In addition, the voltage reference circuit (31) includes a resistor (46), an operational amplifier (44), another plurality of field effect transistors (47, 48) which, in conjunction with one (34) of the pair of bipolar transistors, generates a current (I.sub.2 ') having a negative temperature coefficient. The current (I.sub.1 ') having the positive temperature coefficient is summed with the current (I.sub.2 ') having the negative temperature coefficient to form a current having a zero temperature coefficient, which is used to develop a voltage having a zero temperature coefficient.