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:
Jun. 04, 1991
Filed:
Feb. 01, 1990
Applicant:
Inventors:
Roy Yarbrough, Hiram, ME (US);
Ernest D Haacke, Scaraborough, ME (US);
Lars G Jansson, Long Island, ME (US);
Assignee:
National Semiconductor Corporation, Santa Clara, CA (US);
Primary Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
307456 ; 307290 ; 307359 ;
Abstract
A TTL inverter buffer circuit is provided with a switched current that produces hysteresis in the threshold values. The current is switched on by a control circuit when the input logic is low and off when the logic is high. The control circuit receives its sense from the logic state so that when the input logic is low a high threshold is created and when the input logic is high a low threshold is created. The difference is the circuit hysteresis voltage which is dependent upon the switched current and a resistor.