XRT5894 Datasheet, PDF (2/19 Pages) Exar Corporation – Four-Channel E1 Line Interface (3.3V or 5.0V)

XRT5894
BLOCK DIAGRAM
1:2
TIP
RX Input
RING
RTIP4 (43)
R1
R2
RRING4 (42)
Transceiver 1
Transceiver 2
Transceiver 3
Tranceiver 4
Signal
Peak
Detector
V_CC
RXPOS4 (47)
Receive
Comparators
RXNEG4 (46)
LOSCNT (45)
LOSSEL (25)
LOS
Detect
Loss
CDoeulnatyer
1
Mux
LOS4 (48)
O
Transmit
Line
Drivers
TIP
2:1
R3
TTIP4 (53)
9.1
TX OUTPUT
RING
R4
TRING4 (55)
Pulse
Shaping
9.1
0
0
Mux
1
1
NRZ
To
RZ
Duty
Cycle
Adjust
TXCLK4 (51)
TXPOS4 (49)
TXNEG4 (50)
Figure 1. XRT5894 Block Diagram
Receiver Notes
D The same type 1:2CT ratio transformer may be
used at the receiver input and transmitter output.
D R1 and R2 are both 150W for 75W operation, or
240W for 120W operation.
D Return loss exceeds ITU G.703 specification with
these resistors and a 1:2CT ratio input transformer.
LOS (Loss of Signal) Notes
D LOSSEL (pin 25) is connected to logic “1” for ITU
G.775 compliant LOS delay, or to logic 0 for user
programmable additional delay.
D LOSCNT (pin 45) is unconnected when LOSSEL is
logic 1, or connected to an external clock when
LOSSEL is logic 0.
Transmitter Notes
D Return loss exceeds ETSI 300 166 specification
with a 1:2 ratio transformer.
D R3 and R4 are always 9.1W for both 75W and 120W
applications.
Rev. 1.10
2