- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383602 > MH88632B (Mitel Networks Corporation) Central Office Interface Circuit Preliminary Information PDF資料下載
參數(shù)資料
| 型號： | MH88632B |
| 廠商： | Mitel Networks Corporation |
| 英文描述： | Central Office Interface Circuit Preliminary Information |
| 中文描述： | 中央辦公室接口電路的初步信息 |
| 文件頁數(shù)： | 4/17頁 |
| 文件大?。?/td> | 95K |
| 代理商： | MH88632B |
MH88632B
Preliminary Information
2-242
Functional Description
The MH88632B is a Central Office Interface Circuit
(COIC). It is used to correctly terminate a Central
Office 2-Wire telephone line. The device provides a
signalling link and a 2-4 Wire line interface between
the telephone line and subscriber equipment. The
subscriber equipment can include Private Branch
Exchanges (PBX's), Key Telephone Systems,
Terminal Equipment, Digital Loop Carriers and
Wireless Local Loops.
All descriptions assume that the device is connected
as in the application circuit shown in Figure 3.
Isolation Barrier
The MH88632B provides an isolation barrier which is
designed to meet FCC Part 68 (November 1987)
Leakage Current Requirements.
External Protection
An external protection circuit may be required to
assist in preventing overvoltage damage to the
device and the subscriber equipment in which it is
incorporated. The type of protection required is
dependant on the application and the regulatory
standards. Please contact the governing regulatory
body and local approvals testing houses for more
assistance.
This protection is shown in block form in Figure 3.
Suitable Markets
The programmability offered by the MH88632B
enhances its suitability for use throughout the
world. However, care should be taken that all
regulatory requirements, e.g. isolation and DC
termination, are being fulfilled for the particular
application in which the device is intended to be
used.
Line Termination
When LRC is at a logic 1, LRD is taken to a logic 0
which energizes the Loop Relay (K1), connecting
XLA to XLB and XLC to XLD. This places a line
termination across Tip and Ring. The device can be
considered to be in an off-hook state and DC loop
current will flow. The line termination consists of a
DC resistance and an AC impedance. When LRC is
at a logic 0, the Line Termination is removed from
across Tip and Ring.
An internal Dummy Ringer is permanently connected
across Tip and Ring which is a series AC load of
(17k
+330nF). This represents a mechanical
telephone ringer and allows ringing voltages to be
sensed. This load can be considered negligible
when the line has been terminated.
Depending on the Network Protocol being used the
line termination can seize the line for an outgoing
call, terminate an incoming call, or if applied and
disconnected at the correct rate can be used to
generate dial pulse signals.
The DC line termination circuitry provides the line
with an active DC load which is equivalent to a DC
resistance of between 190
and 290
dependant on
the loop current.
AC Input Impedance
The Input Impedance (Zin) is the AC impedance that
the MH88632B places across Tip and Ring in order
to terminate the telephone line. It can be user
defined, set to 600
or set to 900
.
To select a 600
Input Impedance, Z1 should be
connected directly to Z600. No connection should
be made to Z2 or Z900.
To select a 900
Input Impedance, Z1 should be
connected directly to Z900. No connection should
be made to Z2 or Z600.
In order to user define the Input Impedance an
impedance network should be placed between Z1
and Z2. This should be equivalent to 10 times the
required Input Impedance and must be greater than
100
at 3.4kHz. No connection should be made to
Z600 or Z900.
For example, to implement an Input Impedance of
220
+(820
//115nF) an impedance network of
2200
+(8200
//11.5nF)
between Z1 and Z2 as shown below.
should
be
connected
Z2
Z1
2200
8200
11.5nF
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MH88632BT | Central Office Interface Circuit Preliminary Information |
| MH88634-2 | Central Office Interface Circuit(用于中央辦公電話線的接口電路（在音頻轉(zhuǎn)換設(shè)備和用戶線之間提供一個模擬和信號連接）) |
| MH88634BV-2 | SWITCH PB DPDT MINI RTANG ALTACT |
| MH88634B | Central Office Interface Circuit Advance Information |
| MH88634BT-2 | Central Office Interface Circuit Advance Information |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MH88632BT | 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:Central Office Interface Circuit Preliminary Information |
| MH88633AV-PE4 | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| MH88634 | 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:Central Office Interface Circuit Preliminary Information |
| MH88634-2 | 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:Central Office Interface Circuit Preliminary Information |
| MH88634B | 制造商:MITEL 制造商全稱:Mitel Networks Corporation 功能描述:Central Office Interface Circuit Advance Information |
發(fā)布緊急采購，3分鐘左右您將得到回復。