DS2187

3 of 10

PIN DESCRIPTION Table 1

PIN

SYMBOL

TYPE

DESCRIPTION

1AVDD

-

Analog Positive Supply. 5.0 volts.

2

RAIS

I

Reset Alarm Indication Signal.

Every other low pulse at this input

establishes the AIS alarm detection period.

3

ZCSEN

I

0 Code Suppression Enable.

When high, incoming B8ZS (RCLKSEL=0)

or HDB3 (RCLKSEL=1) code words are replaced with all 0s at RPOS and

RNEG; when low, no code replacement occurs.

4LCAP

-

Loop Cap.

Part of internal loop filter; attach a 10 microfarad capacitor from

5

RCLKSEL

I

Receive Clock Select.

2.048 MHz (CEPT) applications.

6

7

RTIP

RRING

I

Receive Tip and Ring.

Connect to line transformer as shown in Figure 2.

8

LOCK

O

Frequency Lock.

High state indicates that internal circuitry is phase- and

frequency-locked to the incoming signal at RRING and RTIP.

9

AVSS

-

Analog Signal Ground.

0.0 volts.

10

DVSS

-

Digital Signal Ground.

0.0 volts.

11

RCLK

O

Receive Clock.

Extracted line rate clock.

12

13

RNEG

RPOS

O

Receive Data.

Extracted receive data; updated on rising edge of RCLK.

14

NC

-

No Connect.

Do not connect to this pin.

15

BPV

O

Bipolar Violation.

Transitions high for the full bit period when a bit in

violation appears at RPOS or RNEG; B8ZS code words are not accused when

ZCSEN=1. BPV not valid for RCLKSEL=1 and ZCSEN=1.

16

AIS

O

Alarm Indication Signal.

High when the received data stream has contained

less than three 0s during the last two periods of the RAIS signal.

17

RCL

O

Receive Carrier Loss.

High if 192 0s appear at RPOS and RNEG; reset on

next occurrence of a one.

18

DVDD

-

Digital Positive Supply.

5.0 volts