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:
Mar. 26, 1991
Filed:
Sep. 28, 1989
Kenneth M Bell, Windom, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A circuit technique for biasing a complementary NPN-PNP Darlington Emitter Follower Stage without additional biasing resistors or current sources. Four diode-connected transistor are connected in series to provide biasing across the Darlington. Two transistors, one NPN and one PNP, are added with their bases and emitters connected in parallel with the top and bottom diodes, respectively, forming two current mirrors. The collector of the NPN transistor connects to the emitter of the first Darlington NPN transistor. The collector of the PNP transistor connects to the first Darlington PNP transistor. The current mirrors provide equal current to the two first Darlington transistors. These currents are also equal to the current through the four diodes for identically sized transistors.