XRT7302IQ80 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT7302IQ80' PDF : 77 Pages View PDF
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2 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
XRT7302
PIN DESCRIPTION
PIN #
21
SIGNAL NAME
STS-1/DS3_Ch1
22
ICT
23
LOSTHR1
24
LLB1
REV. 1.1.0
TYPE
I
I
I
I
DESCRIPTION
STS-1/DS3 Select Input - Channel 1:
A "high" on this pin configures the Clock Recovery Phase Locked Loop (within
Channel 1) to set its VCO Center frequency to around 51.84 MHz (optimal for
SONET STS-1 operations). A "low" on this pin configures the Clock Recovery
Phase Locked Loop to set the VCO Center frequency to 44.736 MHz (optimal
for DS3 operations).
NOTES:
1. The XRT7302 will ignore this pin if the "E3_Ch1" pin (pin 20) is set to
"1".
2. This input pin is ignored if the XRT7302 is operating in the "Host"
Mode.
3. The user should tie this pin to GND, if the XRT7302 is going to be
operating in the "Host" Mode.
In-Circuit Test Input
Setting this pin "low" causes all digital and analog outputs to go into a high-
impedance state to allow for in-circuit testing. Hence, the user should set this
pin "high" for normal operation.
NOTE: This pin is internally pulled "high".
Loss of Signal Threshold Control - Channel 1
The voltage forced on this pin controls the input loss of signal threshold for
Channel 1. Forcing the LOSTHR1 pin to GND or VDD provides two settings.
This pin must be set to the desired level upon power up and should not be
changed during operation.
NOTE: This pin is only applicable during DS3 or STS-1 operations.
Local Loop-back - Channel 1
This input pin, along with "RLB1" dictates which loop-back mode Channel 1
(within the XRT7302 device) will be operating in.
A "high" on this pin (with "RLB1" being set to "low") configures Channel 1,
within the XRT7302 device to operate in the "Analog Local Loop-back" Mode.
A "high" on this pin (with "RLB1" also being set to "high") configures Channel
1, within the XRT7302 device, to operate in the "Digital Local Loop-back"
Mode and tristates the channel 1 transmitter output.
NOTES:
1. This input pin is ignored if the XRT7302 is operating in the "Host"
Mode.
2. The user should tie this pin to GND, if the XRT7302 is going to be
operating in the "Host" Mode.
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