XRT75R12DIB-F Exar Corporation, XRT75R12DIB-F Datasheet - Page 48

• Manufacturer Part Number: XRT75R12DIB-F
• Description: Peripheral Drivers & Components (PCIs) 12 Channel 3.3V-5V temp -45 to 85C
• Manufacturer: Exar Corporation

Specifications of XRT75R12DIB-F

• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 3.3 V to 5 V
• Package / Case: TBGA-420
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XRT75R12D
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER
This feature is used for monitoring the transmit line for occurrence of fault conditions such as a short circuit on
the line or a defective line driver. To activate this function, connect MTIP_n pins to the TTIP_n lines via a 270
resistor and MRing_n pins to TRing_n lines via 270
When the MTIP_n and MRing_n are connected to the TTIP_n and TRing_n lines, the drive monitor circuit
monitors the line for transitions. The DMO_n (Drive Monitor Output) will be asserted “Low” as long as the
transitions on the line are detected via MTIP_n and MRing_n. If no transitions on the line are detected for 128
± 32 TxClk_n periods, the DMO_n output toggles “High” and when the transitions are detected again, DMO_n
toggles “Low”.
N
The transmitter section of each channel can either be turned on or off. To turn on the transmitter, set the input
pin TxON to “High” and write a “1” to the TxON_n control bit. When the transmitter is turned off, TTIP_n and
TRing_n are tri-stated.
N
F
6.5
6.6
OTE
OTES
IGURE
1.
2.
: The Drive Monitor Circuit is only for diagnostic purpose and does not have to be used to operate the transmitter.
:
33. T
Transmit Drive Monitor
Transmitter Section On/Off
defective line card and turn on the back-up line card, writing a “1” to the TxON_n control bits transfers the control
to TxON pin.
This feature provides support for Redundancy.
If the XRT75R12D is configured in Host mode, to permit a system designed for redundancy to quickly shut-off the
TxLineClk(n)
TxNEG(n)
TxPOS(n)
RANSMIT
D
RIVER
M
ONITOR SET
TPData(n)
TNData(n)
TxClk(n)
-
UP
.
MRing(n)
TRing(n)
MTIP(n)
TTIP(n)
resistor as shown in
44
270
270
R1
R2
31.6 +1%
31.6 + 1%
R1
Figure
R2
33.
1:1
75
R3
REV. 1.0.3