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:
Jul. 21, 1987
Filed:
Jul. 03, 1986
Laszlo V Gal, Poway, CA (US);
Unisys Corporation, Detroit, MI (US);
Abstract
A three-state logic circuit comprising a logic gate on a semiconductor chip which includes first and second conductors, respective resistors connected to the conductors, terminals for receiving input signals, and transistors for generating complementary output signals on the first and second conductors by passing respective currents through the resistors as a logical function of the input signals with the output signals having high and low voltage levels V.sub.H and V.sub.L ; a control circuit on the chip having a first terminal connected to the first conductor, a second terminal connected to the second conductor, and a control terminal for receiving a control signal; a switching circuit within the control circuit which responds to the control signal by passing identical control currents through the respective resistors and into the first and second terminals to thereby lower the voltage levels on both the first and second conductors by at least V.sub.H -V.sub.L ; and first and second driver transistors on the chip and respectively connected to the first and second conductors which drive complementary large and small currents off the chip in response to the voltage levels V.sub.H and V.sub.L, and which drive no more than the small current off the chip in response to the lowered voltage levels.