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:
Sep. 23, 1986
Filed:
Jan. 27, 1984
Fujitsu Limited, Kawasaki, JP;
Abstract
In an output transistor of transistor-transistor logic (TTL) circuits, an output transistor of TTL is provided with, in a region between a p-type base region and the p-type semiconductor substrate on which a TTL circuit is fabricated, a p.sup.- diffusion which causes carriers stored in the base region when the output transistor is switched from ON state to OFF state to be discharged quickly. When the output transistor is OFF, the p.sup.- diffusion is pinched off and no current flows. Thus, when the output transistor is switched from OFF state to ON state, the output voltage changes sharply. Because of this, the switching speed of the TTL is improved. In another embodiment, a p.sup.- region is formed between a p-type base region and p.sup.+ isolation diffusion, and an n.sup.+ diffusion is formed to cover at least one part of the p.sup.- diffusion and is connected to an n-type collector region. In another embodiment, a p-type base region extends to the p.sup.+ isolation diffusion, and an n.sup.+ diffusion is formed in a region between the base region and the isolation diffusion and is connected to an n-type collector region.