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:
Oct. 11, 1977
Filed:
Mar. 22, 1976
David L Cave, Tempe, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
There is disclosed a constant current source device comprising a diffused integrated circuit resistor in combination with a junction field effect transistor (FET). The FET is fabricated having an ion-implanted channel and diffused regions of the same conductivity type of material as the channel material, the diffused regions constitute the Source and Drain electrodes of the FET. The use of ion-implantation enables a tight tolerance to be maintained on the pinch-off voltage (V.sub.P) characteristics of the FET. By extending the source diffusion region the diffused resistor is produced integral with the FET and has a constant and known, but high temperature coefficient (TC). By taking advantage of the high TC of the resistor and the controlled V.sub.P of the FET, the combining structure provides a constant current having a substantially zero temperature coefficient over the temperature range from -50.degree. C to +125.degree. C.