摘要 |
A line interface includes a transmit path for an electrical signal, a receive path for an electrical signal, and a reference path coupled from the output of the transmit path to the receive path. The reference path including a filter for matching the impedance of the telephone line. The transmit path has an output coupled to the primary winding of a transformer. The secondary winding of the transformer is adapted to be coupled to a telephone line. The receive path has an input coupled to the primary winding and the reference path includes means for inverting an electrical signal, thereby providing a hybrid coupling function.
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