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:
May. 21, 1985
Filed:
Jan. 20, 1984
James W Davis, Boca Raton, FL (US);
Frank D Jones, Wallkill, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A bipolar transistor integrated circuit PLA is disclosed. The array includes a first and second mutually isolated epitaxial regions in a semiconductor substrate. A plurality of common collector bipolar transistors are formed in the first epitaxial region with selected ones of the plurality having their emitters connected in common to a first current source. A second plurality of common collector bipolar transistors in the second epitaxial region have the emitters of selected ones of the second plurality connected in common to the first epitaxial region. The bases of the corresponding pairs of transistors from the first and second epitaxial region are connected to an input signal source. The second epitaxial region is connected to an output node. In this manner, a cascode connected PLA is formed which eliminates the need for surplus current sources required in the prior art. The dot OR formed by the circuit effectively merges the prior art OR array with the search array.