參數(shù)資料
型號(hào)： MH88610
廠商： Mitel Networks Corporation
英文描述： Subscriber Line Interface Circuit (SLIC) Preliminary Information
中文描述： 用戶(hù)線接口電路（SLIC）的初步信息
文件頁(yè)數(shù)： 3/8頁(yè)
文件大?。?/td> 63K
代理商： MH88610
Preliminary Information
MH88610
2-99
Functional Description
The MH88610 performs a transformerless 2-wire to
4-wire conversion of the analog signal. The 2-wire
circuit is the balanced line going to the subscriber
loop, while the 4-wire circuit is the audio signal going
to an from devices such as the voice codec or
switching circuit. The SLIC also provides two status
signals. switch hook (SHK) and loop length (Loop).
The Loop signal is an analog voltage which is
proportional to the loop length and the SHK goes low
when the telephone set is off-hook.
Constant Current Feed
The MH88610 employs a complex feedback circuit to
supply a constant feed current to the line. This is
done by sensing the sum of the voltages across the
internal feed resistors and comparing it to an input
reference voltage (VRef) that determines the
constant feed current. This gives the loop current as:
I
Loop
= 25 - (VRef) mA (
+
2 mA)
1.25
Switch Hook Detection
When the DC current exceeds an internal threshold
level, the switch hook (SHK) will go low. If the loop
resistance is so high that V
Bat
can no longer supply
the required amount of loop current as determined
by constant current supply circuit, the output of the
switch hook (SHK) will go high impedance (open
collector output) to indicate that the loop resistance
is too high and the line is on hook.
Ringing And Ring Trip Detection
In Figure 3 a ringing signal (e.g., 90Vrms=+/-48Vdc)
is applied to the line by disconnecting pin 15 (RV)
from pin 11(RF), and connecting the ringing voltage
at pin 11 (RF) by use of the relay K1.
The SLIC can detect an off-hook condition during
ringing but there is a large AC component which
must be filtered out to give a true off-hook condition
at SHK.
A 1.0
μ
F capacitor connected from pin 19 (CAP) to
ground will provide adequate attenuation when
ringing is applied. Once an off-hook condition has
been detected an external circuit will deactivate the
relay (K1) to disconnect the ringing voltage from pin
11 and reconnect to pin 15. At that time the SLIC will
revert to constant current feed operation.
For applications requiring Dial Pulse Detection the
Capacitor connection to ground should be controlled
such that the capacitor is only connected during
ringing.
During off-hook conditions (closed loop), the
capacitor should be switched out. This can be
performed using a transistor, relay or system drive
output of a codec. Applying GNDA to the Ring Trip
Filter Control pin will switch in the filter, whilst
removing GNDA, (with the switch in a tristate
condition), will switch out the filter.
For applications
capacitor can be permanently connected to ground.
using
DTMF signalling, the
Current Limit
The Tip or Ring may accidentally short to ground. In
such a case, current will only flow through the feed
resistor. This high current will be sensed and
reduced by the current limit circuit to a lower value to
protect the internal circuitry.
Components List
R1
R2
R3
R4
R5
R6
RV1*, RV2*
D1*, D3*, D4*
D2
D5
Q
K1
C1*,C2*,C3*,C4*= Cap. Cer., 1.0
μ
F, 50V, 20%
C5
=Cap. Elec., 1.0
μ
F, 16V 10%
=Resistor 1/4w, + 5%, 30.0k
=Resistor 1/4w, + 5%, 750k
=Resistor 1/4w, + 5%, 3.9k
=Resistor 1/4w, + 5%, 4.7k
=Resistor 1/4w, + 5%, 43k
=Resistor 1/4w, + 5%, 470k
=Var. 160 VRMS, 250V,10J
=Diode Rect., 200V, 1A IN4003
=Diode Rect., 200V, 1A IN4003
=Diode Sw., 75V, 02A, 0.5W IN4148
=NPN, 2N2222 or equivalent
=Relay E/M, 12V, 1 form C
Note: Components marked * are optional for extra protection of
the hybrid.
相關(guān)PDF資料
PDF描述
MH88612BV-K Subscriber Line Interface Circuit (SLIC)(混合用戶(hù)線接口電路（SLIC）)
MH88612B Subscriber Line Interface Circuit (SLIC)(混合用戶(hù)線接口電路（SLIC）)
MH88612C Subscriber Line Interface Circuit Preliminary Information
MH88612K Subscriber Line Interface Circuit Preliminary Information
MH88612 Subscriber Line Interface Circuit (SLIC) Preliminary Information
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MH88612 制造商:MITEL 制造商全稱(chēng):Mitel Networks Corporation 功能描述:Subscriber Line Interface Circuit (SLIC) Preliminary Information
MH88612B 制造商:ZARLINK 制造商全稱(chēng):Zarlink Semiconductor Inc 功能描述:Subscriber Line Interface Circuit (SLIC)
MH88612BV-2 制造商:ZARLINK 制造商全稱(chēng):Zarlink Semiconductor Inc 功能描述:Subscriber Line Interface Circuit (SLIC)
MH88612BV-K 制造商:MITEL 制造商全稱(chēng):Mitel Networks Corporation 功能描述:Subscriber Line Interface Circuit (SLIC) Advance Information
MH88612C 制造商:MITEL 制造商全稱(chēng):Mitel Networks Corporation 功能描述:Subscriber Line Interface Circuit Preliminary Information
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*