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.

Date of Patent:
Dec. 22, 1987

Filed:

Jul. 10, 1986
Applicant:
Inventor:

Einar O Traa, Portland, OR (US);

Assignee:

Tektronix, Inc., Beaverton, OR (US);

Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G05F / ;
U.S. Cl.
CPC ...
323314 ; 323907 ; 323315 ;
Abstract

A voltage reference circuit (10) for a constant-current source transistor (16) of the bipolar type provides an output voltage in two components. The first voltage component varies in accordance with the negative temperature coefficient (C.sub.1) of the base (58)-emitter (78) junction of a bipolar transistor (60) to compensate for temperature-related changes in the base (18)-to-emitter (22) voltage of the constant current source transistor. The second voltage component is of fixed magnitude and develops collector current (I.sub.0) flow through the transistor and thereby actuates constant-current source operation. The result is a transistor constant-current source that provides a constant output current independent of temperature.


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