PBL 386 20/2
14
15
16
17
18
19
20
21
22
DR
C3
C2
C1
DET
NC
VCC
PLD
POV
Input to the ring trip comparator. With DR more positive than DT the detector output, DET, is at logic
level low, indicating off-hook condition. The external ring trip network connects to this input.
C1, C2 and C3 are digital inputs (internal pull-up) controlling the SLIC operating states.
Refer to section "Operating states" for details.
Detector
output. Active low when indicating loop detection and ring trip, active high when indicating ground
key detection.
No
internal
Connection.
+5 V power supply.
Programmable Loop Detector
threshold. The loop detection threshold is programmed by a resistor
connected from this pin to AGND.
Programmable Overhead Voltage.
If pin is left open: The overhead voltage is internally set to min 1.0 V in
Off-and On-hook. If a resistor is connected between this pin and AGND: the overhead voltage can be set to
higher values.
Prog. Line Current,
the constant current part of the DC feed characteristic is programmed by a resistor
connected from this pin to AGND.
A
Reference,
49.9 kΩ, resistor should be connected from this pin to AGND.
No
internal
Connection.
Receive Summing Node.
200 times the AC-current flowing into this pin equals the metallic (transversal) AC-
current flowing from RINGX to TIPX. Programming networks for two-wire impedance and
receive gain connect to the receive summing node. A resistor should be connected from this pin to AGND.
Analog Ground, should be tied together with BGND.
Transmit vf output. The AC voltage difference between TIPX and RINGX, the AC metallic voltage, is
reproduced as an unbalanced GND referenced signal at VTX with a gain of one (or one half, see pin PTG).
The two-wire impedance programming network connects between VTX and RSN.
23
24
25
26
PLC
REF
NC
RSN
27
28
AGND
VTX
SLIC Operating States
State
0
1
2
3
4
5
6
7
Table 1.
C3
C2
C1
SLIC operating state
Open circuit
Ringing state
Active state
Not applicable
Not applicable
Active state
Not applicable
Not applicable
Active detector
-
Ring trip detector (active low)
Loop detector (active low)
-
-
Ground key detector (active high)
-
-
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
SLIC operating states.
9
ERICSSON [ ERICSSON ]
