PBL 386 50/2

9

15

C3

C1, C2 and C3 are digital inputs (internal pull-up) controlling the SLIC operating states.

16

C2

Refer to section "Operating states" for details.

17

C1

18

DET

Detector output. Active low when indicating loop detection and ring trip, active high when indicating

ground key detection.

19

NC

No internal Connection

20

VCC

+5 V power supply.

21

PLD

Programmable Loop Detector threshold. The loop detection threshold is programmed by a resistor

connected from this pin to AGND.

22

POV

Programmable Overhead Voltage. If pin is left open: The overhead voltage is internally set to min 2.7 V in

off-hook and min 1.1 V in On-hook. If a resistor is connected between this pin and AGND: the overhead

voltage can be set to higher values.

23

PLC

Prog. Line Current, the current limit,reference C in figure 13, is programmed by a resistor connected from

this pin to AGND.

24

REF

A Reference, 49.9 k

Ω, resistor should be connected from this pin to AGND.

25

NC

No internal Connection

26

RSN

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.

27

AGND

Analog Ground, should be tied together with BGND.

28

VTX

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 0.5 (or 0.25, see pin PTG).

The two-wire impedance programming network connects between VTX and RSN.

SLIC Operating States

State

C3

C2

C1

SLIC operating state

Active detector

0000

Open circuit

-

1001

Ringing state

Ring trip detector (active low)

2010

Active state

Loop detector (active low)

3011

Active state

Line voltage measurement (note 9)

4100

Tip open state

Loop detector (active low)

5101

Active state

Ground key detector (active high)

6110

Active reverse

Loop detector (active low)

7111

Active reverse

Ground key detector (active high)

Table 1. SLIC operating states.

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