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:
Dec. 16, 1980
Filed:
Feb. 15, 1979
Tom L Blackburn, San Jose, CA (US);
GTE Automatic Electric Laboratories Incorporated, Northlake, IL (US);
Abstract
An integrated current source comprising a discrete resistor having one side thereof electrically connected through a PNP transistor to a first DC supply voltage and through series connected base-emitter diodes of a first pair of NPN transistors to a temperature stable DC supply voltage. The other side of the resistor is electrically connected to ground through series connected base-emitter junctions of a second pair of NPN transistors, with the base emitter junctions of the first and second transistor pairs being poled in opposite directions. The NPN transistors are caused to have collector currents that make the base-emitter junction voltages cancel on opposite sides of the resistor. This causes the temperature stable supply voltage to be established across the resistor in order to set a reference current in it, and in an NPN transistor driving the load, that is substantially constant and independent of temperature.