Digital data and orderwire combiner apparatus

摘要

A digital data and orderwire combiner employs a first and a second inverting gate amplifiers. The first amplifier receives the orderwire signal which is a low rate digital signal, while the second amplifier receives the data signal which is of a higher rate. The amplifiers have a common ground return where current through the amplifiers is directed through a resistive impedance network. The amplifiers as coupled together providing a 3-level amplitude modulated signal indicative of the combined data and orderwire signal. In order to reduce jitter, a portion of one of the signals is directed from one amplifier to the other. The configuration assure low jitter operation while producing reliable voltage levels indicative of 3-level amplitude modulation.