XRT83VSH28ES Exar, XRT83VSH28ES Datasheet - Page 24

• Manufacturer Part Number: XRT83VSH28ES
• Description: Peripheral Drivers & Components - PCIs 8 CH E1 LIU SH (low cost version)
• Manufacturer: Exar

Specifications of XRT83VSH28ES

• Product Category: Peripheral Drivers & Components - PCIs
• Rohs: yes

XRT83VSH28
8-CHANNEL E1 SHORT-HAUL LINE INTERFACE UNIT
Along with the internal termination, a high precision external fixed resistor can be used to optimize the return
loss. This external resistor can be used for all modes of operation ensuring one bill of materials. There are
three resistor values that can be used by setting the RxRES[1:0] bits in the appropriate channel register.
Selecting the value for the external fixed resistor is shown in
By default, RxRES[1:0] is set to "None" for no external fixed resistor. If an external fixed resistor is used, the
XRT83VSH28 uses the parallel combination of the external fixed resistor and the internal termination as the
input impedance. See
N
F
2.1.2
OTE
IGURE
: Without the external resistor, the XRT83VSH28 meets all return loss specifications. This mode was created to add
flexibility for optimizing return loss by using a high precision external resistor.
5. T
CASE 2: Internal Termination With One External Fixed Resistor for All Modes
YPICAL
C
ONNECTION
T
Figure 5
ABLE
Internal Impedance
XRT83VSH28 LIU
3: S
for a typical connection diagram using the external fixed resistor.
D
ELECTING THE
R
IAGRAM
X
0h (00)
1h (01)
2h (10)
3h (11)
RES[1:0]
Receiver
Input
U
SING
R
R
RING
TIP
V
ALUE OF THE
O
NE
R=320, 280, or 190
E
21
XTERNAL
R
E
Table
XTERNAL
E
XTERNAL
1:1
F
IXED
3.
320
280
190
None
F
IXED
R
Line Interface E1
F
ESISTOR
IXED
R
ESISTOR
R
ESISTOR
REV. 2.0.0