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. 17, 1983
Filed:
May. 26, 1981
Jesse B Lipcon, Harvard, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A transceiver for a carrier-sense multiple access communications network using collision detection for controlling access to the network, and utilizing industry standard emitter-coupled logic (ECL) circuits in its receiver and transmitter. The transmitter output stage is an ECL current source. To prevent saturation of the transmitter output in the event of a collision, due to the voltage swing exceeding the compliance limit of the ECL current source, with a resulting failure of the collision detection mechanism, the power supply for the transmitter output stage supplies voltage in a first range of about -5 to -10 volts, while the power supply for the receiver input and collision detection circuits supplies voltage in a second, contiguous range of zero to about -5 volts. This permits the transmitter output to swing about 6-7 volts without exceeding the compliance limit of the current source, so that the collision is detectable by the collision detection circuits.