Channel unit interface circuit
US4993063A · kind A · utility
Inventor
Key dates
| Filing date | Dec 27, 1988 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Dec 27, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04Q1/50
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A channel unit interface circuit for interconnecting a two-wire, bidirectional signal transmitting path and a four-wire signal transmitting path in a communication system includes a tip terminal transconductance amplifier driver, a ring terminal transconductance amplifier driver, a voice sense amplifier, a balance network, A/D signal processing circuit, D/A signal processing circuit, filter network, a voice codec/PCM filter, a channel logic circuit, and a DC-to-DC converter. The tip terminal transconductance driver is formed of a first switching operational amplifier, and the ring terminal transconductance driver is formed of a second switching operational amplifier. Each of the first and second switching operational amplifiers is formed of a low voltage transconductance amplifier, high voltage comparator, a filter network, and a feed forward compensation amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.