pbl386302 ETC-unknow, pbl386302 Datasheet - Page 14

• Manufacturer Part Number: pbl386302
• Description: Subscriber Line Interface Circuit
• Manufacturer: ETC-unknow

Analog Temperature Guard
The widely varying environmental condi-
tions in which SLICs operate may lead to
the chip temperature limitations being ex-
ceeded. The PBL 386 30/2 SLIC reduce
the dc line current when the chip tempera-
ture reaches approximately 145 C and in-
creases it again automatically when the
temperature drops. Accordingly transmis-
sion is not lost under high ambient tem-
perature conditions.
logic low level when the temperature guard
is active.
PBL 386 30/2
14
Figure 12. Battery feed characteristics (without the protection resistors on the line).
The detector output, DET, is forced to a
A:
B:
C:
D:
I
R
I
V
R
L
LConst
TR
feedB
Feed
(@ V
= |V
(typ)= I
=
= 2
TR
R
Bat
SG
= 0V) = I
·
| - V
30 k
+ 2
LProg
200
OHvirt
A
A
·
=
10
LProg
- R
10
4
R
LC
Feed
3
+
|V
- 4
·
Bat
(I
·
10
LProg
| - V
-3
+ 4
OHVirt
60
·
10
B
·
- R
10
-3
)
Feed
3
Loop Monitoring Functions
The loop current and ring trip detector
report their status through a common out-
put, DET. The detector to be connected to
DET is selected via the two bit wide control
interface C1 and C2. Please refer to sec-
tion Control Inputs for a description of the
control interface.
Loop Current Detector
that the telephone is off hook and that
current is flowing in the loop by putting the
output DET to a logical low level when
selected.The loop current threshold value,
I
changes state is programmable by select-
ing the value of resistor R
between pin PLD and ground and is calcu-
LTh
·
The loop current detector is indicating
(I
, at which the loop current detector
LProg
C
+ 4
DC characteristics
·
10
-3
)
V
TR
D
[V]
B
LD
. R
E:
F:
G:
H:
J:
LD
IL
Apparent battery V
R
V
Virtual battery V
connects
TROpen
feedG
6 mA
= 2
= |V
·
25
Bat
| - V
lated according to
and is not influenced by the ac signal at the
two wire side.
Ring Trip Detector
Ring trip detection is accomplished by con-
necting an external network to a compara-
tor in the SLIC with inputs DT and DR. The
ringing source can be balanced or unbal-
anced superimposed on V
unbalanced ringing source may be applied
to either the ring lead or the tip lead with
return via the other wire. A ring relay driven
by the SLIC ring relay driver connects the
ringing source to tip and ring.
BatVirt
R
The current detector is internally filtered
OH
C
Bat
LD
D
F
(@ IL = 4 mA) = |V
(@ I
= 500
J
L
I
= 0) =|V
LTh
F
Bat
E
| - V
H
G
Bat
OHvirt
| - V
- R
OHVirt
Feed
B
or GND. The
·
4
·
10
-3
)