Electronic inductor with transmit signal telephone line driver
US6584196B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1999 |
| Grant date | Jun 24, 2003 |
| Priority date | — |
| Expiry date | May 14, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/0278
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In an electronic inductor circuit, an operational amplifier drives the base of the electronic inductor transistor, and receives negative feedback from the emitter of the transistor. The transistor and operational amplifier combine to form a voltage-controlled current source (VCCS) with respect to the loop current. A voltage divider connected across the rectified Tip and Ring voltage (or another node of the circuit at an equivalent voltage) provides a DC reference to the positive input of the operational amplifier, so that the line current automatically increases with an increase in line voltage. A capacitor couples the transmit signal driver to the positive input of the operational amplifier. This electronic inductor circuit can be driven using a low voltage supply and provides sufficient linearity for high-speed modem applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.