
DS26518 8-Port T1/E1/J1 Transceiver
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8.
PIN DESCRIPTIONS
8.1
Pin Functional Description
Table 8-1. Detailed Pin Descriptions
NAME
PIN
TYPE
FUNCTION
ANALOG TRANSMIT
Transmit Bipolar Tip for Transceiver 1 to 8.
These pins are differential line
driver tip outputs. These pins can be high impedance if:
If TXENABLE is low, TTIPn/TRINGn will be high impedance. Note that if
TXENABLE is low, the register settings for control of TTIPn/TRINGn are ignored
and output is high impedance.
The differential outputs of TTIPn and TRINGn can provide internal matched
impedance for E1 75
Ω
, E1 120
Ω
, T1 100
Ω
, or J1 110
Ω
. The user can turn off
internal termination.
Note:
The two pins shown for each transmit bipolar tip (e.g., pins A1 and A2 for
TTIP1) should be tied together.
Transmit Bipolar Ring for Transceiver 1 to 8.
These pins are differential line
driver ring outputs. These pins can be high impedance if:
If TXENABLE is low, TTIPn/TRINGn will be high impedance. Note that if
TXENABLE is low, the register settings for control of TTIPn/TRINGn are ignored
and output is high impedance.
The differential outputs of TTIPn and TRINGn can provide internal matched
impedance for E1 75
Ω
, E1 120
Ω
, T1 100
Ω
, or J1 110
Ω
. The user can turn off
internal termination.
Note:
The two pins shown for each transmit bipolar ring (e.g., pins A3 and B3 for
TRING1) should be tied together.
Transmit Enable.
If this pin is pulled low, all transmitter outputs (TTIPn and
TRINGn) are high impedance. The register settings for tri-state control of
TTIPn/TRINGn are ignored if TXENABLE is low. If TXENABLE is high, the
particular driver can be tri-stated by the register settings.
TTIP1
TTIP2
TTIP3
TTIP4
TTIP5
TTIP6
TTIP7
TTIP8
TRING1
TRING2
TRING3
TRING4
TRING5
TRING6
TRING7
TRING8
A1, A2
H1, H2
J1 J2
T1, T2
T15, T16
J15, J16
H15, H16
A15, A16
A3, B3
G3, H3
J3, K3
R3, T3
R14,T14
J14, K14
G14, H14
A14, B14
Analog
Output,
High
Impedance
Analog
Output,
High
Impedance
TXENABLE/
SCAN_EN
L13
Input
Scan Enable.
When low, device is in normal operation. Scan enable is selected
by the SCANMODE pin.
Note:
User should not select scan enable—test mode
only.
ANALOG RECEIVE
RTIP1
RTIP2
RTIP3
RTIP4
RTIP5
RTIP6
RTIP7
RTIP8
RRING1
RRING2
RRING3
RRING4
RRING5
RRING6
RRING7
RRING8
C1
F1
L1
P1
P16
L16
F16
C16
C2
F2
L2
P2
P15
L15
F15
C15
Analog
Input
Receive Bipolar Tip for Transceiver 1 to 8.
The differential inputs of RTIPn
and RRINGn can provide internal matched impedance for E1 75
Ω
, E1 120
Ω
, T1
100
Ω
, or J1 110
Ω
. The user can turn off internal termination via the LIU Receive
Impedance and Sensitivity Monitor register (
LRISMR
).
Analog
Input
Receive Bipolar Ring for Transceiver 1 to 8.
The differential inputs of RTIPn
and RRINGn can provide internal matched impedance for E1 75
Ω
, E1 120
Ω
, T1
100
Ω
, or J1 110
Ω
. The user has the option of turning off internal termination via
the LIU Receive Impedance and Sensitivity Monitor register (
LRISMR
).
RESREF
J5
Input
Resistor Reference.
This pin is used to calibrate the internal impedance match
resistors of the receive LIUs. This pin should be tied to V
SS
through a 10k
Ω
±
1%
resistor.