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. 07, 1992
Filed:
May. 15, 1990
Richard M Kerslake, Bedford, GB;
Frank R Fattori, Clapham, GB;
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A line interface circuit sends two-level signals to a line and receives two-level signals from a line. The two levels of the signals are on opposite sides of a threshold range of levels. For testing the circuit the transmitter is connected to the receiver by a switchable path, and a test signal is produced by the transmitter for reception by the receiver for monitoring the functioning of the circuit. The test signal is of a small amplitude so as not to enter the threshold range of levels). The connections of the transmitter and receiver to the line are maintained during testing. During testing the output of the transmitter is limited in amplitude by a voltage clamp so that it can produce only the test signal.