xrt83l30 Exar Corporation, xrt83l30 Datasheet - Page 30

• Manufacturer Part Number: xrt83l30
• Description: Xrt83l30 -single-channel T1/e1/j1 Long-haul, Short-haul Line Interface Unit
• Manufacturer: Exar Corporation

XRT83L30
SINGLE-CHANNEL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
TRANSMIT AND RECEIVE TERMINATIONS
The XRT83L30 is a versatile LIU that can be programmed to use one Bill of Materials (BOM) for worldwide
applications for T1, J1 and E1. For specific applications the internal terminations can be disabled to allow the
use of existing components and/or designs.
RECEIVER
I
In Hardware mode, RXTSEL (Pin 44) can be tied “High” to select internal termination mode or tied “Low” to
select external termination mode. By default the XRT83L30 is set for external termination mode at power up or
at Hardware reset.
In Host mode, bit 7 in the appropriate register,
on page
F
If the internal termination mode (RXTSEL = “1”) is selected, the effective impedance for E1, T1 or J1 can be
achieved either with an internal resistor or a combination of internal and external resistors as shown in
NTERNAL
IGURE
RNEG
TNEG
RPOS
TPOS
RCLK
TCLK
13. S
47), is set “High” to select the internal termination mode for the receive channel.
R
ECEIVE
IMPLIFIED
Line Driver
T
Equalizer
ERMINATION
TX
RX
D
IAGRAM FOR THE
M
ODE
T
ABLE
RXTSEL
R
R
int
int
0
1
6: R
I
NTERNAL
R
int
ECEIVE
(Table 20, “Microprocessor Register #1, Bit Description,”
RRING
TRING
TTIP
RTIP
R
T
ECEIVE AND
27
ERMINATION
RX TERMINATION
0.68µF
EXTERNAL
INTERNAL
T
RANSMIT
C
ONTROL
1
4
5
8
1:2
1:1
T1
T2
T
ERMINATION
5
1
8
4
M
ODE
RTIP
RRING
TTIP
TRING
75 Ω, 100 Ω
110 Ω or 120 Ω
75 Ω, 100 Ω
110 Ω or 120 Ω
REV. 1.0.1
Table
7.