XRT73L03IV datasheet(38/62 Pages) EXAR

38 / 62 page

XRT73L03

3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT

áç

PRELIMINARY

REV. P1.0.13

3.2

THE RECEIVE EQUALIZER BLOCK

The purpose of this block is to equalize the incoming

distorted signal due to cable loss. The Receive

Equalizer attempts to restore the shape of the line

signal so that the transmitted data and clock can be

recovered reliably.

• Design Considerations for DS3 and STS-1

Applications

When installing equipment into environments depict-

ed in Figure 19, we recommend that the Receive

Equalizer be enabled by setting the REQDIS(n) input

pin for Channel(n) or the respective bit-fields to "0".

The only time that the Receive Equalizer should be

disabled is when an off-chip equalizer is in the Re-

ceive path between the Digital Cross-Connect system

and the RTIP/RRing input pins, or in applications

where the Receiver is monitoring the transmit output

signal directly.

• Design Considerations for E3 Applications or if

the Overall Cable Length is known

Figure 19 indicates the following:

a. The length of cable between the Transmitting Ter-

minal and the Digital Cross-Connect system can

range between 0 and 450 feet.

b. The length of cable between the Digital Cross-Con-

nect system and the Receive Terminal can range be-

tween 0 and 450 feet.

Consequently, the overall cable length between the

Transmitting Terminal and the Receiving Terminal can

range between very short cable length (e.g., near 0

feet) up to 900 feet.

If during System Installation the overall cable length is

known, to optimize the performance of the XRT73L03

in terms of receive jitter performance, etc., enable or

disable the Receive Equalizer based upon the follow-

ing recommendations:

The Receive Equalizer should be turned ON if the

Receive Section of a given channel is going to re-

FIGURE 19. THE TYPICAL APPLICATION FOR THE SYSTEM INSTALLER

Digital Cross-Connect

System

Transmitting

Terminal

Receiving

Terminal

0 to 450 feet of Cable

Pulses that are

compliant to the

Isolated DSX-3 or

STSX-1 Pulse Template

Requirement

0 to 450 feet of

Cable

DSX-3

STSX-1

XRT73L03IV Datasheet(PDF) 38 Page - Exar Corporation

XRT73L03IV Datasheet(HTML) 38 Page - Exar Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62

Datasheet Download

Link URL