Tracking voltage regulator for a subscriber line i

专利名称：Tracking voltage regulator for a subscriber

line interface circuit

发明人：Russell J. Apfel申请号：US115878申请日：20061227

公开号：US20080159525A1公开日：20080703

专利附图：

摘要：In one embodiment, the present invention includes an apparatus having a firstpair of low voltage operational amplifiers to generate an output representative of anabsolute value difference of first and second line voltages of a subscriber loop, and a

third low voltage operational amplifier having an input coupled to the output of the firstpair of low voltage operational amplifiers to filter the output and to provide a switchcontrol signal for a switching regulator that provides a voltage used to generate the firstand second line voltages. The apparatus may include additional circuits such as a limitcircuit to limit the input to the third low voltage operational amplifier and one or morespeedup circuits to reduce a filter time constant of the third low voltage operationalamplifier during a ringing mode of the subscriber loop.

申请人：Russell J. Apfel

地址：Austin TX US

国籍：US

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