Patents Examined by Jack P. Harvey
  • Patent number: 5778204
    Abstract: A bus circuit for implementing a high speed dominant logic bus for a differential signal. The bus circuit is useful in a communication network having a plurality of multi-port nodes that are coupled by point-to-point links that communicate differential signals. Each port in the node includes a bus driver that receives the differential signal received at the port. The bus driver supplies a differential current signal to a first bus. A terminator circuit is coupled to the first differential bus, to receive the differential current signals supplied from the ports. The terminator circuit, responsive to the differential current signal, outputs a differential voltage signal indicative of either a dominant state or a non-dominant state to a second differential bus, which is coupled to the plurality of ports for transmission. A biasing circuit for the bus drivers allows operation at low voltages, and furthermore insures the zero crossing of the differential voltage signal on the second differential bus.
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: July 7, 1998
    Assignee: Apple Computer, Inc.
    Inventors: Roger W. Van Brunt, Florin Oprescu