Patent ID: 6492880
Filing Date: 2002-12-10
Classification: H04L

Abstract:
A common mode termination comprising:a differential voltage transmitter having a transmitter differential output; a transmit isolation transformer having a primary and a secondary, said transmit isolation transformer primary coupled to said transmitter differential output; a transmit common mode transformer having an input and an output, said transmit common mode transformer input coupled to said transmit isolation transformer secondary; a transmit reference autotransformer having an output, a compliment output, and a center tap, said transmit reference transformer output and compliment output coupled to said common mode transformer output; a shielded connector having at least two pins for a line output, said pins coupled to said transmit common mode transformer; a differential voltage receiver having a receiver differential input; a receive isolation transformer having a primary and a secondary, said receive isolation transformer primary coupled to said receive differential input; a receive common mode transformer having an input and an output, said input coupled to said receive isolation transformer secondary; a receive reference autotransformer having an output, a compliment output, and a center tap, said receive reference transformer output and compliment output coupled to said receive common mode transformer output; a shielded connector having at least two pins for a line input, said pins coupled to said receive common mode transformer; a voltage source common mode transformer having an input and an output,.said common mode transformer output coupled to said transmit reference autotransformer center tap and said receive reference autotransformer center tap; a voltage source having an output and a return, said voltage source output coupled to said voltage source common mode transformer input.