XRT83SL38ES Exar, XRT83SL38ES Datasheet - Page 36

• Manufacturer Part Number: XRT83SL38ES
• Description: Peripheral Drivers & Components - PCIs 8 CHT1/E1LIUSH
• Manufacturer: Exar

Specifications of XRT83SL38ES

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

XRT83SL38
OCTAL T1/E1/J1 SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
TRANSMITTER (CHANNELS 0 - 7)
T
In Hardware mode, TXTSEL (Pin 84) can be tied “High” to select internal termination mode for all transmit
channels or tied “Low” for external termination. Individual channel control can be done only in Host mode. In
Host mode, bit 6 in the appropriate register for a given channel is set “High” to select the internal termination
mode for that specific transmit channel, see
page 52.
For internal termination, the transformer turns ratio is always 1:2. In internal mode, no external resistors are
used. An external capacitor of 0.68μF is used for proper operation of the internal termination circuitry, see
Figure
E
By default the XRT83SL38 is set for external termination mode at power up or at Hardware reset.
When external transmit termination mode is selected, the internal termination circuitry is disabled. The value of
the external resistors is chosen for a specific application according to the turns ratio selected by TRATIO (Pin
127) in Hardware mode or bit 0 in the appropriate register for a specific channel in Host mode, see
and
RANSMIT
XTERNAL
Table 22, “Microprocessor Register #3, Bit Description,” on page
10.
T
T
ERMINATION
RANSMIT
F
IGURE
T
12. S
ERMINATION
X R T 8 3 S L 3 8 L IU
M
TXTSEL
ODE
IMPLIFIED
0
1
T R IN G
TERSEL1
R R IN G
T T IP
R T IP
T
M
T
ABLE
0
0
1
1
ODE
ABLE
D
IAGRAM FOR
8: T
9: T
RANSMIT
Table 20, “Microprocessor Register #1, Bit Description,” on
ERMINATION
7 5
TX TERMINATION
TERSEL0
9 .1
9 .1
Ω
EXTERNAL
INTERNAL
E1
0
1
0
1
Ω
Ω
T
34
IN
ERMINATION
E
S
XTERNAL
ELECT
1 :2 .4 5
1 :1
TERMINATION
C
C
T
ONTROL
100 Ω
120 Ω
ERMINATION
110 Ω
ONTROL
75 Ω
T
X
T
RANSFORMER
56.
7 5
7 5
1:2.45
Figure 11
1:2
M
Ω
Ω
ODE
(RXTSEL= 0)
R
ATIO
is a simplified block
REV. 1.0.2
Table 10