发明名称 |
Digital access arrangement circuitry and method for connecting to phone lines having a DC holding circuit with switchable time constants |
摘要 |
A digital direct access arrangement (DAA) circuitry may be used to terminate the telephone connections at the user's end that provides a communication path for signals to and from the phone lines. Briefly described, the DAA provides a programmable means for the DC termination for a variety of international phone standards. The invention may also be utilized with means for transmitting and receiving a signal across a capacitive isolation barrier. More particularly, a DC holding circuit is provided that has switchable time constants. A first time constant may be utilized during a first operation phase immediately after off-hook conditions to allow for fast settling times. Then, a second operation phase is entered in which a second time constant may be utilized. During the second operation phase the DC holding circuit operates slower to create improved low frequency performance.
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申请公布号 |
US6201865(B1) |
申请公布日期 |
2001.03.13 |
申请号 |
US19980097621 |
申请日期 |
1998.06.16 |
申请人 |
SILICON LABORATORIES, INC. |
发明人 |
DUPUIS TIMOTHY J.;TUTTLE GEORGE TYSON;SCOTT JEFFREY W.;SOOCH NAVDEEP S.;WELLAND DAVID R. |
分类号 |
H04L7/033;H04L25/06;H04M11/06;H04M19/00;(IPC1-7):H04M11/00 |
主分类号 |
H04L7/033 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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