MH88634-2

Preliminary Information

2-266

Figure 2 - Pin Connections

Pin Description

Pin #

Name

Description

1

TIP

Tip Lead. Connects to the "Tip" lead of a Telephone Line.

2

RING

Ring Lead. Connects to the "Ring" lead of a Telephone Line.

3

XLA

Loop Relay Contact A. Connects to XLB through the Loop relay (K1) contacts when the

relay is activated.

4

XLD

Loop Relay Contact D. Connects to XLC through the loop relay (K1) contacts, when the

relay is activated.

5

XLB

Loop Relay Contact B. Connects to XLA through the loop relay (K1) contacts, when the

relay is activated.

6

XLC

Loop Relay Contact C. Connects to XLD through the loop relay (K1) contacts, when the

relay is activated.

7-9

IC

Internal Connection. No connection should be made to this pin.

10

SHK

Switch Hook (Output). A logic 0 indicates the presence of forward or reverse battery

voltage when LRC is logic 0 and the presence of forward or reverse loop current when LRC

is logic 1.

11

RX

Receive (Input). 4-Wire ground (AGND) referenced analog input.

12

VEE

Negative Supply Voltage. -5V DC

13

TX

Transmit (Output). 4-Wire ground (AGND) referenced analog output.

14

RV

Ringing Voltage Detect (Output). A logic low indicates that ringing voltage is across the Tip

and Ring leads.

15

FL

Forward Loop Detect (Output). In the on-hook state, a logic 0 output indicates that

forward loop battery is present. In the off-hook state, a logic 0 indicates that forward loop

current is present.

16

RL

Reverse Loop Detect (Output). In the on-hook state, a logic 0 output indicates that

reverse loop battery is present. In the off-hook state, a logic 0 output indicates that reverse

loop current is present.

17

VCC

Positive Supply Voltage. +5V DC

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

TIP

RING

XLA

XLB

XLC

IC

IC

IC

RX

VEE

TX

RV

FL

RL

VCC

AGND

LRC

VRLY

LRD

21

XLD

SHK

21

20

19

18

17

16

15

14

13

12

11

10

9

8

6

5

4

3

2

1

7