XRT7295ATIW Exar Corporation, XRT7295ATIW Datasheet - Page 13

• Manufacturer Part Number: XRT7295ATIW
• Description: DS3/SONET STS-1 Line Receiver
• Manufacturer: Exar Corporation

Specifications of XRT7295ATIW

• Lead Free Status / RoHS Status: Contains lead / RoHS Compliant

Notes
- Lower threshold is 1.5 dB below upper threshold.
- The RLOS alarm is an indication of the absence of an input signal, not a bit error rate indication (independent of the RLOS state). The
device will attempt to recover correct timing data. The RLOS low-to-high transition typically occurs 1dB below the high to low transi-
tion.
RECOVERED CLOCK AND DATA TIMING
Table 7 and Figure 11 summarize the timing relationships
between the logic signals RCLK, RPDATA, and RNDATA.
The duty cycle is referenced to V
RPDATA and RNDATA change on the rising edge of
RCLK and are valid during the falling edge of RCLK. A
positive pulse at R
a low level on RNDATA. A negative pulse at the input
creates a high level on RNDATA and a low level on
RPDATA, and a received zero produces low levels on
both RPDATA and RNDATA.
Rev.1.20
STS-1
Data
Rate
DS3
IN
creates a high level on RPDATA and
REQB
0
1
0
1
DD
Table 6. Analog Loss-of-Signal Thresholds
/2 threshold level.
LOSTHR
V
V
V
V
V
V
V
V
DD
DD
DD
DD
0
0
0
0
DD
DD
DD
DD
/2
/2
/2
/2
13
IN-CIRCUIT TEST CAPABILITY
When pulled low, the ICT pin forces all digital output
buffers (RCLK, RPDATA, RNDATA, RLOS, RLOL pins) to
be placed in a high output impedance state. This feature
allows in-circuit testing to be done on neighboring devices
without concern for XRT7295AT device buffer damage.
An internal pull-up device (nominally 50kW) is provided on
this pin therefore, users can leave this pin unconnected
for normal operation. Test equipment can pull ICT low
during in-circuit testing without damaging the device.
This is the only pin for which internal pull-up/pull-down is
provided.
Threshold
Min.
60
40
25
45
30
20
75
50
30
55
35
25
Threshold
XRT7295AT
Max.
220
145
175
115
275
185
115
220
145
90
70
90
mV pk
mV pk
mV pk
mV pk
mV pk
mV pk
mV pk
mV pk
mV pk
mV pk
mV pk
mV pk
Unit