摘要 |
A data access arrangement generates a first current in a first current path which runs from a tip terminal of a line pair through a light emitting diode of an opto-isolator to a sense node. The data access arrangement also generates a second current in a second current path that runs from the tip terminal to the sense node. The first current is modulated in response to an audio input signal received from the telephone line pair, while the second current is modulated in response to a potential generated at the sense node, such that a third current flowing from the sense node to the ring terminal remains at a substantially constant predetermined magnitude.
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