6

20

PRI

A TTL compatible input used to control PR. PRI active High = PR active low.

21

PR

An active low open collector output. Can be used to drive a Polarity Reversal Relay.

22

DG

Digital Ground - To be connected to zero potential. Serves as a reference for all digital inputs and outputs on

the SLIC.

23

RD

Ring Relay Driver - An active low open collector output. Used to drive a relay that switches ringing signals onto

the 2-Wire line.

24

VFB

Feedback input to the tip feed amplifier; may be used in conjunction with transmit output signal and the spare

op amp to accommodate 2-Wire line impedance matching.

25

Tip Feed - A low impedance analog output connected to the TIP terminal through a feed resistor. Functions

with the RF terminal to provide loop current, and to feed voice signals to the telephone set and to sink longitu-

NA

26

Ring Feed - A low impedance analog output connected to the RING terminal through a feed resistor. Functions

with the TF terminal to provide loop current, feed voice signals to the telephone set, and to sink longitudinal

NA

27

VB-

The battery voltage source. The most negative supply.

28

BG

Battery Ground - To be connected to zero potential. All loop current and some quiescent current flows into this

ground terminal.

NC

No internal connection.

NOTE:

to run separate grounds off a line card, the AG must be applied first.

SOIC

SYMBOL

DESCRIPTION

HC-5509B3999-003