Inventors:
Lazar Lvovsky - Walnut Creek CA
V. Bruce Hunt - Menlo Park CA
Assignee:
Metapath Inc. - Foster City CA
International Classification:
H03L 318
H04B 2549
Abstract:
A method and apparatus for generating bipolar pulses in a local area network is disclosed comprising a transmitter. In the transmitter there is provided a pair of transistors which are coupled together in a resistor network. A capacitor is provided for coupling the transistors and resistor network to a transmission line. In operation, the output impedance of the transmitter is low when either of the transistors is conducting and high when neither of the transistors is conducting. To generate Alternate Mark Inversion pulses, both transistors are turned on. Thereafter, and in response to a signal corresponding to a logical 1, one of the transistors is turned off and then turned on for generating a positive pulse on the transmission line. Upon the occurrence of a subsequent control signal corresponding to the next logical 1, the other of the transistors is turned off and then on for producing a negative pulse on the transmission line. By alternately turning the transistors on and off upon the occurrence of control signals corresponding to each logical 1, Alternate Mark Inversion pulses are produced on the transmission line.