发明授权
- 专利标题: Subscriber line interface circuit
- 专利标题(中): 用户线接口电路
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申请号: US232844申请日: 1988-08-16
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公开(公告)号: US4866767A公开(公告)日: 1989-09-12
- 发明人: Hiroshi Tanimoto , Minoru Tanaka , Satoru Yoshida
- 申请人: Hiroshi Tanimoto , Minoru Tanaka , Satoru Yoshida
- 申请人地址: JPX Kawasaki
- 专利权人: Kabushiki Kaisha Toshiba
- 当前专利权人: Kabushiki Kaisha Toshiba
- 当前专利权人地址: JPX Kawasaki
- 优先权: JPX62-206421 19870821
- 主分类号: H04M19/00
- IPC分类号: H04M19/00 ; H04Q3/42
摘要:
The subscriber line interface circuit comprises subscriber nodes, reception nodes and transmission nodes, a power feeding unit, adders, impedance elements, an inverting amplifier, and a feedback element. The subscriber nodes are coupled to a subscriber terminal via a subscriber line, and the reception and transmission nodes are coupled to an exchange via a reception line and a transmission line, respectively. The feeding unit supplied a DC current to the terminal and controls the current. The first adder adds the voltage between the subscriber nodes and the voltage from the reception node. The first impedance element has an impedance corresponding to a real-number multiplication of the impedance between the subscriber nodes, and is applied with the output voltage of the first adder. The amplifier is given with the output of the first impedance element. The second impedance element, inserted in the feedback path of the amplifier, has an impedance corresponding to a real-number multiplication of the impedances of the subscriber line and the terminal. The feedback element supplies, to the feeding unit, a signal corresponding to the current flowing through the first impedance element as a control signal. The second adder adds the output voltage of the amplifier, the output voltage of the first adder and the voltage of the reception nodes, and supplies the resultant signal to the transmission nodes.
公开/授权文献
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