Low noise line powered DAA with differential feedback
US6731728B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1998 |
| Grant date | May 4, 2004 |
| Priority date | — |
| Expiry date | Apr 7, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M19/001
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A telephone line interface or data access arrangement (DAA) is provided which draws power for the customer premises equipment from the telephone line. The DAA includes a shunt regulator as the power source drawing power from the telephone line, and a line modulator in series with the shunt regulator. A sense resistor is placed in series between the line modulator and shunt regulator to sense the line current. Accordingly, DC termination and AC modulation characteristics as presented by the DM to the telephone line can be adjusted by variation of an AC signal with DC offset input to the amplifier driving the line modulator without requiring a different DAA for use in regions or countries having various DC termination and AC modulation requirements. The differential feedback from a sense resistor reduces the noise induced in the circuit from the shunt regulator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.