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:
Nov. 05, 1996
Filed:
Apr. 18, 1994
Kouzou Ichimaru, Kunisaki-machi, JP;
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A semiconductor integrated circuit for performing a current mirror function and capable of operating stably at a low supply voltage to yield an output current nearly equal to the reference current. The current mirror circuit includes a pair of horizontal type pnp transistors and a vertical type npn transistor having an area almost equal to that of either of the pair of horizontal transistors, the vertical type npn transistor being used as a reverse transistor. A current source supplies the base current of the horizontal transistors as well as the collector current of the vertical transistor. Because of its structure, it is possible for the vertical transistor to have a base area and static forward current transfer ratio greater than those of the horizontal transistors. Since the emitter area of the vertical transistor is large, even when it is used to function as a reverse transistor, its static forward current transfer ratio is high. Through using this vertical transistor as a reverse transistor, the effect of the base current of the horizontal transistors on the reference current is reduced.