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US 5,602,912 AGranted
Telephone hybrid circuit
AssigneeSilicon Systems, Inc.
InventorRussell A. Hershbarger
Life of this patent
Estimating the term…
Abstract
A method and apparatus for providing a telephone hybrid function is provided. The present invention maximizes dynamic range while providing a receive signal without interference from a transmit signal. The present invention also provides single-ended to differential conversion. The present invention may be practiced with an integrated circuit powered by a telephone line and coupled to the telephone line without the need for a high voltage isolation barrier between the integrated circuit and the telephone line.
Claims8
A method for providing a telephone hybrid function comprising the steps of:
- connecting a first input of a telephone hybrid function means for providing a telephone hybrid function to a first telephone line conductor;
- connecting ground of said telephone hybrid function means to a second telephone line conductor, isolating ground of said telephone hybrid function means from earth ground;
- receiving a telephone line signal at said first input of said telephone hybrid function means, said telephone line signal comprising a first transmit signal and a receive signal;
- receiving a second transmit signal at a second input of said telephone hybrid function means;
- highpass filtering said telephone line signal;
- highpass filtering said second transmit signal;
- converting said receive signal to a differential receive signal, using a converting means;
- canceling said first and second transmit signals using a canceling means, to prevent said first and second transmit signals from being outputted;
- outputting said differential receive signal, without outputting said first and second transmit signals.
6 more elements
A hybrid circuit comprising:
- a first input, a second input, and an output;
- a first telephone line conductor coupled to said first input, said telephone line conductor carrying a first transmit signal and a receive signal;
- a node coupled to said second input, said node carrying a second transmit signal;
- a converting means for converting said receive signal to a differential receive signal, said converting means having a first input coupled to said first input of said hybrid circuit, said converting means having a second input coupled to said second input of said hybrid circuit, and said converting means having a differential output coupled to said output of said hybrid circuit;
- a canceling means for canceling said first transmit signal and said second transmit signal, said canceling means having a first input coupled to said first input of said hybrid circuit, said canceling means having a second input coupled to said second input of said hybrid circuit, and said canceling means having a differential output coupled to said output of said hybrid circuit;
- said output, of said hybrid circuit, providing said differential receive signal without providing said first and second transmit signals.
3 more elements
Dependencies are inferred from the claim text.