KR970031688A

KR970031688A - Subscriber line interface circuit

Info

Publication number: KR970031688A
Application number: KR1019950039751A
Authority: KR
Inventors: 장현정
Original assignee: 김광호; 삼성전자 주식회사
Priority date: 1995-11-04
Filing date: 1995-11-04
Publication date: 1997-06-26

Abstract

본 발명은 가입자 라인 인터페이스 회로를 공개한다. 그 회로는 교환기와 가입자 전화기를 인터페이스하기 위한 인터페이스 수단, 상기 가입자 전화기와 상기 인터페이스 수단을 연결하기 위한 제1 및 2선로, 상기 인터페이스 수단과 상기 제1선로 또는 상기 제1선로와 전원전압의 연결을 제어하기 위한 제1스위칭수단, 상기 제1선로와 제2선로 사이에 직렬연결된 제2스위칭 수단 및 전류제한수단, 상기 전류 제한수단을 통과하는 전류와 비교전류를 비교하기 위한 비교수단, 및 상기 비교수단의 출력신호에 응답하여 상기 인터페이스 수단 및 상기 제1, 제2스위칭수단을 제어하기 위한 제어수단으로 구성되어 있다. 따라서, 전화기가 잘못 놓여진 경우에 종래의 가입자 라인 인터페이스 회로는 오프되고, 제어회로, 비교기 및 카운터만 동작하게 되고, 이들 회로의 동작은 낮은 전원전압만으로도 가능하므로 전력소모를 줄일 수 있게 된다.The present invention discloses a subscriber line interface circuit. The circuit comprises interface means for interfacing the exchange and the subscriber telephone, first and second lines for connecting the subscriber telephone and the interface means, and connection of the power supply voltage with the interface means and the first line or the first line. A first switching means for controlling, a second switching means and a current limiting means connected in series between the first line and the second line, comparison means for comparing a current passing through the current limiting means with a comparison current, and the comparison Control means for controlling the interface means and the first and second switching means in response to an output signal of the means. Therefore, when the telephone is misplaced, the conventional subscriber line interface circuit is turned off, and only the control circuit, the comparator and the counter are operated, and the operation of these circuits is possible even with a low power supply voltage, thereby reducing power consumption.

Description

Subscriber line interface circuit

본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음Since this is an open matter, no full text was included.

제1도는 본 발명의 가입자 라인 인터페이스 회로를 나타내는 것이다.1 shows a subscriber line interface circuit of the present invention.

제2도는 거리(R_T)에 대한 기준전류(Iref)의 변화를 나타내는 그래프이다.2 is a graph showing a change in the reference current Iref with respect to the distance R _T.

Claims

Interface means for interfacing the exchange and the subscriber telephone; First and second lines for connecting said subscriber telephone with said interface means; First switching means for controlling a connection between the interface means and the first line or the first line and a power supply voltage; Second switching means and current limiting means connected in series between the first line and the second line; Comparison means for comparing a current passing through the current limiting means with a comparison current; And control means for controlling said interface means and said first and second switching means in response to an output signal of said comparing means.

2. The subscriber line interface circuit of claim 1 wherein the subscriber line interface circuit is coupled to the exchange.

The control means according to claim 1, wherein the control means causes the first switching means to connect the interface means and the first line when the telephone is in an off hook state, the second switching means is turned off, and the interface means is turned off. To be in an active state, to cause the first switching means to connect the power supply voltage to the first line when the telephone is on hook, to turn on the second switching means, and to open the interface means. Subscriber line interface circuit.

※ Note: The disclosure is based on the initial application.