參數(shù)資料
型號(hào)： L8551
廠商： Lineage Power
英文描述： Low-Power SLIC(低功耗用戶線接口（SLIC）)
中文描述： 低功耗用戶接口（低功耗用戶線接口電路（SLIC））
文件頁(yè)數(shù)： 20/32頁(yè)
文件大?。?/td> 526K
代理商： L8551
20
Lucent Technologies Inc.
Data Sheet
March 1997
L8551 Low-Power SLIC
Applications
(continued)
dc Applications
Battery Feed
The dc feed characteristic can be described by:
(
R
L
where:
I
L
= dc loop current.
V
T/R
= dc loop voltage.
|
V
BAT
|
= battery voltage magnitude.
V
OH
= overhead voltage. This is the difference between
the battery voltage and the open loop Tip/Ring
voltage.
R
L
= loop resistance, not including protection resistors.
R
P
= protection resistor value.
R
DC
= SLIC internal dc feed resistance.
The design begins by drawing the desired dc template.
An example is shown in Figure 26.
Notes: V
BAT
= –48 V; I
LIM
= 22 mA; R
DC1
= 115
.
12-3050 (C)
Figure 26. Loop Current vs. Loop Voltage
Starting from the on-hook condition and going through
to a short circuit, the curve passes through two regions:
Region 1: On-hook and low loop currents. The slope
corresponds to the dc resistance of the SLIC, R
DC1
(de-
fault is 110
typical). The open circuit voltage is the
battery voltage less the overhead voltage of the device,
V
OH
(default is 6.5 V typical). These values are suitable
for most applications, but can be adjusted if needed. For
more information, see the sections entitled Adjusting dc
Feed Resistance and Adjusting Overhead Voltage.
Region 2: Current limit. The dc current is limited to a val-
ue determined by external resistor R
PROG
. This region of
the dc template has a high resistance (10 k
).
Calculate the external resistor as follows:
R
PROG
(k
) = 1.67 I
LIM
(mA)
Overhead Voltage
In order to drive an on-hook ac signal, the SLIC must
set up the Tip and Ring voltage to a value less than the
battery voltage. The amount that the open loop voltage
is decreased relative to the battery is referred to as the
overhead voltage. Expressed as an equation,
V
OH
= |V
BAT
| – (V
PT
– V
PR
)
Without this buffer voltage, amplifier saturation will
occur and the signal will be clipped. The L7551 is auto-
matically set at the factory to allow undistorted on-hook
transmission of a 3.17 dBm signal into a 900
loop
impedance. For applications where higher signal levels
are needed, e.g., periodic pulse metering, the 2-wire
port of the SLIC can be programmed with pin DCR.
The drive amplifiers are capable of 4 Vrms minimum
(V
AMP
). Referring to Figure 27, the internal dc output
resitance in Tip or Ring has a worst-case value of
65
. This is equal to one-half the maximum dc feed
resistance. So, the maximum signal the device can
guarantee is:
=
Where R
P
is the series protection resistor (assume
20
), and R
S
is the worst case on resistance of the
L7581 solid-state switch which is 28
.Thus, R
P
+ R
S
<
48
allows 2.2 V
rms
metering signals. The next step is
to determine the amount of overhead voltage needed.
The peak voltage at output of Tip and Ring amplifiers is
related to the peak signal voltage by:
+
I
L
R
L
+
R
DC
+
2R
P
-----------------------------------
=
V
T/R
V
BAT
---------------------------------------------
V
OH
–
)
R
DC
R
×
L
2R
P
+
+
=
L
0
10
20
50
0
20
30
40
50
LOOP VOLTAGE (V)
30
40
10
1
10 k
I
LIM
–1
R
DC1
V
T/R
4 V
Z
T/R
2 R
P
R
S
65
+
+
)
+
----------------------------------------------------
Vamp = V
T/R
1
2 R
P
R
S
Z
T/R
65
+
+
)
Λ
Λ
相關(guān)PDF資料
PDF描述
L8560 Low-Power SLIC（electronic subscriber loop interface circuits ） with Ringing(帶振鈴的低功耗用戶線接口（SLIC）)
L8567 SLIC for People Republic of China Applications(用于中國(guó)的用戶線接口（SLIC）)
L8574D Resistive Subscriber Line Interface Circuit (SLIC), Ring Relay, and Protector (SRP) for Long Loop and TR-57 Applications(長(zhǎng)環(huán)路和TR-57應(yīng)用的電阻性用戶線接口，振鈴繼電器和保護(hù)器)
L8575 Dual-Resistive, Low-Cost Subscriber Line Interface Circuit (SLIC)(雙電阻、低價(jià)格用戶線接口)
L8576B Dual Ringing SLIC(雙通道振鈴用戶環(huán)路接口（SLIC）)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L8560 制造商:AGERE 制造商全稱:AGERE 功能描述:Low-Power SLIC with Ringing
L8560AAU 制造商:Alcatel-Lucent 功能描述: 制造商:LUCENT 功能描述:
L8561 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:The UTC L8561 is a Power Factor Corrector, which can work in wide input voltage range applications (from 85V ~ 265V) with an excellent THD.
L8561_11 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:POWER FACTOR CORRECTOR
L8561G-D08-T 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:POWER FACTOR CORRECTOR
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

*
*
*