Circuit for the implementation of an impedance for a telephone speech circuit
US5459787A · kind A · utility
4Cited by
2References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 21, 1993 |
| Grant date | Oct 17, 1995 |
| Priority date | — |
| Expiry date | Jul 21, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M1/76
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A circuit for synthesizing an impedance associated with a telephone subscriber's circuit connected to a two-wire telephone line is described. The circuit of the invention is adapted to synthesize a complex impedance which can function both as a termination impedance and a balance impedance. The termination impedance utilizes a positive feedback loop structure having a loop gain which is at all times less than unity. The circuit that implements both the termination and balance impedances with sidetone suppression is also described. Each of the embodiments is realizable with a single external component consisting of a resistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.