欧美成人免费电影,国产欧美一区二区三区精品酒店,精品国产a毛片,色网在线免费观看

參數資料
型號: L8560
英文描述: Low-Power SLIC with Ringing
中文描述: 低功耗振鈴用戶接口
文件頁數: 37/46頁
文件大小: 842K
代理商: L8560
Data Sheet
April 2000
Lucent Technologies Inc.
37
L8560 Low-Power SLIC with Ringing
Applications
(continued)
Design Considerations
(continued)
Table 13 shows the design parameters of the application circuit shown in Figure 35. Components that are adjusted
to program these values are also shown.
Table 13. 600
Design Parameters
Design Parameter
Parameter Value
10 mA
25 mA
55
3.14 dBm
600
600
0 dB
0 dB
Components Adjusted
R
LCTH
R
PROG
R
T3
, R
GP
, R
RCV
R
HB1
R
T6
, R
X
R
RCV
, R
GP
, R
T3
Loop Closure Threshold
dc Loop Current Limit
dc Feed Resistance
2-wire Signal Overload Level
ac Termination Impedance
Hybrid Balance Line Impedance
Transmit Gain
Receive Gain
ac Design
There are four key ac design parameters.
Termination
impedance
is the impedance looking into the 2-wire
port of the line card. It is set to match the impedance of
the telephone loop in order to minimize echo return to
the telephone set.
Transmit gain
is measured from the
2-wire port to the PCM highway, while
receive gain
is
done from the PCM highway to the transmit port.
Finally, the
hybrid balance
network cancels the
unwanted amount of the receive signal that appears at
the transmit port.
At this point in the design, the codec needs to be
selected. The discrete network between the SLIC and
the codec can then be designed. Below is a brief codec
feature and selection summary.
First-Generation Codecs
These perform the basic filtering, A/D (transmit), D/A
(receive), and
μ
-law/A-law companding. They all have
an op amp in front of the A/D converter for transmit gain
setting and hybrid balance (cancellation at the summing
node). Depending on the type, some have differential
analog input stages, differential analog output stages,
and
μ
-law/A-law selectability. This generation of codec
has the lowest cost. It is most suitable for applications
with fixed gains, termination impedance, and hybrid bal-
ance.
Second-Generation Codecs
This class of devices includes a microprocessor inter-
face for software control of the gains and hybrid bal-
ance. The hybrid balance is included in the device. ac
programmability adds application flexibility and saves
several passive components. It also adds several I/O
latches that are needed in the application. It does not
have the transmit op amp, since the transmit gain and
hybrid balance are set internally.
Third-Generation Codecs
This class of devices includes the gains, termination im-
pedance, and hybrid balance—all under microproces-
sor control. Depending on the device, it may or may not
include latches.
In the codec selection, increasing software control and
flexibility are traded for device cost. To help decide, it
may be useful to consider the following: Will the appli-
cation require only one value for each gain and imped-
ance Will the board be used in different countries with
different requirements Will several versions of the
board be built If so, will one version of the board be
most of the production volume Does the application
need only real termination impedance Does the hybrid
balance need to be adjusted in the field
相關PDF資料
PDF描述
L8567 SLIC for Peoples Republic of China Applications
L8567-32PLCC Telecommunication IC
L8567-44PLCC Telecommunication IC
L8574D CAP 15PF 50V 5% C0G SMD-0402 TR-7-PA SN100
L8575 Dual-Resistive,Low-Cost Subscriber Line Interface Circuit(SLIC)
相關代理商/技術參數
參數描述
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
L8561G-S08-R 制造商:UTC-IC 制造商全稱:UTC-IC 功能描述:POWER FACTOR CORRECTOR
主站蜘蛛池模板: 乌兰察布市| 曲水县| 新疆| 昭苏县| 凭祥市| 乌兰浩特市| 绍兴市| 寿阳县| 曲麻莱县| 东莞市| 曲沃县| 乐安县| 泾源县| 陵川县| 封开县| 密山市| 茶陵县| 温泉县| 葵青区| 大田县| 南阳市| 苍溪县| 绿春县| 乌兰浩特市| 隆安县| 宜良县| 武强县| 五寨县| 泊头市| 庆阳市| 贡觉县| 阳西县| 休宁县| 沂源县| 桐乡市| 乌拉特后旗| 陆良县| 霍林郭勒市| 曲麻莱县| 泰安市| 白水县|