欢迎访问ic37.com |
会员登录 免费注册
发布采购

PBL38630/2QNS 参数 Datasheet PDF下载

PBL38630/2QNS图片预览
型号: PBL38630/2QNS
PDF下载: 下载PDF文件 查看货源
内容描述: [SLIC, 2-4 Conversion, Bipolar, PQCC28, PLASTIC, LCC-28]
分类和应用: 电信电信集成电路
文件页数/大小: 16 页 / 132 K
品牌: ERICSSON [ ERICSSON ]
 浏览型号PBL38630/2QNS的Datasheet PDF文件第6页浏览型号PBL38630/2QNS的Datasheet PDF文件第7页浏览型号PBL38630/2QNS的Datasheet PDF文件第8页浏览型号PBL38630/2QNS的Datasheet PDF文件第9页浏览型号PBL38630/2QNS的Datasheet PDF文件第11页浏览型号PBL38630/2QNS的Datasheet PDF文件第12页浏览型号PBL38630/2QNS的Datasheet PDF文件第13页浏览型号PBL38630/2QNS的Datasheet PDF文件第14页  
PBL 386 30/2  
Four-Wire to Two-Wire Gain  
From (1), (2) and (3) with EL = 0:  
TIPX  
TIP  
I
+
L
VTR  
R
R
P
F
G42  
=
=
Z
L
VRX  
Z
+
TR  
VTX  
V
TR  
RHP  
G
+
ZT  
ZL  
2-4S  
-
+
ZT  
αRSN  
E
ZRX  
L
V
+ G24S (ZL + 2RF + 2RP)  
TX  
R
R
P
-
F
-
I
L
RING  
RINGX  
-
Z
T
For applications where  
Z
RX  
ZT/(αRSN·G2-4S) + 2RF + 2RP is chosen to be  
equaltoZL theexpressionforG4-2 simplifies  
to:  
RSN  
+
V
RX  
I
/αRSN  
L
-
PBL 386 30/2  
ZT  
1
G42 = −  
ZRX 2G24S  
Figure 8. Simplified ac transmission circuit.  
Four-Wire to Four-Wire Gain  
Functional Description  
andApplicationsInforma-  
tion  
From (1), (2) and (3) with EL = 0:  
VTX  
G44  
=
=
VRX  
ZT  
G24S (ZL + 2RF + 2RP)  
+ G24S (ZL + 2RF + 2RP )  
ZT  
αRSN  
VRX is the analog ground referenced re-  
ceive signal.  
ZRX  
Transmission  
General  
αRSN is the receive summing node current  
to metallic loop current gain = 200.  
A simplified ac model of the transmission  
circuitsisshowninfigure8. Circuitanalysis  
yields:  
Hybrid Function  
Note that the SLICs two-wire to four-wire  
gain, G2-4S, is user programmable between  
two fix values. Refer to the datasheets for  
The hybrid function can easily be imple-  
mented utilizing the uncommitted amplifier  
inconventionalCODEC/filtercombinations.  
Please, refer to figure 9. Via impedance ZB  
a current proportional to VRX is injected into  
the summing node of the combination  
CODEC/filter amplifier. As can be seen  
from the expression for the four-wire to  
four-wire gain a voltage proportional to VRX  
isreturnedtoVTX. Thisvoltageisconverted  
by RTX to a current flowing into the same  
summing node. These currents can be  
made to cancel by letting:  
values on G2-4S  
.
VTX  
(1)  
VTR  
=
+ IL (2RF + 2RP )  
G24S  
VTX VRX  
Two-Wire Impedance  
IL  
+
=
(2)  
(3)  
To calculate ZTR, the impedance presented  
to the two-wire line by the SLIC including  
the fuse and protection resistors RF and RP,  
let:  
ZT  
ZRX  
αRSN  
VTR = EL - IL · ZL  
where:  
VRX = 0.  
VTX is a ground referenced version of the  
acmetallicvoltagebetweentheTIPX  
and RINGX terminals.  
G2-4S is the programmable SLIC two-wire  
to four-wire gain (transmit direction).  
See note below.  
From (1) and (2):  
VTX VRX  
ZT  
+
= 0(EL = 0)  
ZTR  
=
+ 2RF + 2RP  
RTX  
ZB  
αRSN G24S  
The four-wire to four-wire gain, G4-4, in-  
cludes the required phase shift and thus  
the balance network ZB can be calculated  
from:  
ThuswithZTR,αRSN,G2-4S,RP andRF known:  
ZT = αRSN G24S (ZTR 2RF 2RP )  
VTR is the ac metallic voltage between  
tip and ring.  
V
EL  
is the line open circuit ac metallic  
voltage.  
RX  
Z
= −R  
=
B
TX  
V
TX  
Two-Wire to Four-Wire Gain  
Z
IL  
is the ac metallic current.  
is a fuse resistor.  
is part of the SLIC protection  
is the line impedance.  
determines the SLIC TIPX to RINGX  
impedance at voice frequencies.  
T
From (1) and (2) with VRX = 0:  
+ G  
(Z + 2R + 2R )  
L F P  
24S  
RF  
RP  
ZL  
ZT  
Z
α
RX  
RSN  
G
R
TX  
Z
(Z + 2R + 2R )  
24S L F P  
T
VTX  
VTR  
ZT / αRSN  
G24  
=
=
ZT  
αRSN G24S  
+ 2RF + 2RP  
ZRX controls four- to two-wire gain.  
10