Drive circuit
US6795549B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2001 |
| Grant date | Sep 21, 2004 |
| Priority date | — |
| Expiry date | Dec 21, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/267
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Driver circuit for driving voice and data signals from a switching center via a subscriber line (38) to a subscriber terminal, having:a controllable voice signal driver (12) which has a high output impedance in a quiescent operating mode and, in a working operating mode, drives an analog voice signal from the switching center via the subscriber line (38) to the subscriber terminal, with a low output impedance;a controllable data signal driver, which has a high output impedance in the quiescent operating mode and, in the working operating mode, drives an analog-modulated data signal in a data transmission frequency band (&Dgr;f) from the switching center via the subscriber line (38) to the subscriber terminal;an identification circuit (27), which, in the quiescent operating mode, identifies a current rise in a current flowing via the subscriber line (38) when the subscriber terminal is picked up, and produces a pick-up identification signal;and having a CODEC circuit (4), which, on receiving the pick-up identification signal from the identification circuit (27) switches the voice signal driver (12) from the quiescent operating mode to the working operating mode and disconnects the i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.