Circuit for joint transmitting voice and data over a telephone line
AssigneeInfineon Technologies AG
InventorBernhard Zojer
Life of this patent
Estimating the term…
Abstract
The invention relates to an SLIC circuit (1), which is connected directly to a telephone line (2), for joint transmission of voice and data via the telephone line (2), with adequate echo attenuation achieved even at high data frequencies in that a first current which corresponds to the sum of the transmission and received currents (Ia, Ib), and a second current (Id) which corresponds to the current produced by the transmission power level (Vtx) at the data frequency, are produced, and the difference between the first current and the second current (Id) is emitted.
Claims10
A circuit (1) for joint transmission of voice and data via a telephone line (2),
- having a first and a second telephone line connection (TIP, RING) for connection to the telephone line (2),
- having a data connection (ITD) for connection to a data line (3),
- having first circuit means (T1-T4, R3, R4), which are coupled to the telephone line connections (TIP, RING) for producing a first current which is composed of the sum of transmission and received currents (Ia, Ib) which flow via the telephone line (2) and are produced via a transmission power level (Vtx) and a received power level (Vrx), respectively, and
- having second circuit means (T5, R1-2, C1-C2) which are coupled to the telephone line connections (TIP, RING) for producing a second current (Id) which corresponds to the current produced solely by the transmission power level corresponding to the data,
- with the outputs of the first circuit means (T1-T4, R3, R4) and of the second circuit means (T5, R1-R2, C1-C2) being coupled to the data connection (ITD) in such a manner that a current (Ic) which is emitted via the data connection (ITD) corresponds to the difference between the first current and the second current (Id).
Dependencies are inferred from the claim text.