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. 03, 1984
Filed:
Apr. 05, 1982
Myron J Koen, Tucson, AZ (US);
Burr-Brown Research Corp., Tucson, AZ (US);
Abstract
A precision current source includes a current source transistor and a current steering circuit which selectively directs the output current from the current source transistor through either a first or a second current path in response to a digital input signal. A compensation circuit directs a highly accurate steady state current through first and second series coupled compensation transistors. The base of the second compensation transistor is coupled to the base of the current source transistor. The compensation circuit operates to control the voltage differential between the base of the current source transistor and a voltage source to maintain the output current intermittently steered through the second current path precisely constant regardless of changes in the beta of the current switching transistor or changes in the beta or base to emitter voltage of the current source transistor.