Datasheet

DS26514 4-Port T1/E1/J1 Transceiver
19-5856; Rev 4; 5/11 20 of 305
8. PIN DESCRIPTIONS
8.1 Pin Functional Description
Table 8-1. Detailed Pin Descriptions
NAME PIN TYPE FUNCTION
ANALOG TRANSMIT
TTIP1 A1, A2
Analog
Output,
High
Impedance
Transmit Bipolar Tip for Transceiver 1 to 4. 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 75Ω, E1 120Ω, T1 100Ω, or J1 110Ω. 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.
TTIP2 H1, H2
TTIP3 J1 J2
TTIP4 T1, T2
TRING1 A3, B3
Analog
Output,
High
Impedance
Transmit Bipolar Ring for Transceiver 1 to 4. 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 75Ω, E1 120Ω, T1 100Ω, or J1 110Ω. 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.
TRING2 G3, H3
TRING3 J3, K3
TRING4 R3, T3
TXENABLE/
SCAN_EN
L13 Input
Transmit Enable. If this pin is pulled low, all transmitter outputs (TTIPn and
TRINGn) are high impedance. The register settings for three-state control of
TTIPn/TRINGn are ignored if TXENABLE is low. If TXENABLE is high, the
particular driver can be three-stated by the register settings.
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 C1
Analog
Input
Receive Bipolar Tip for Transceiver 1 to 4. The differential inputs of RTIPn
and RRINGn can provide internal matched impedance for E1 75Ω, E1 120Ω, T1
100Ω, or J1 110Ω. The user can turn off internal termination via the LIU Receive
Impedance and Sensitivity Monitor register (
LRISMR).
RTIP2 F1
RTIP3 L1
RTIP4 P1
RRING1 C2
Analog
Input
Receive Bipolar Ring for Transceiver 1 to 4. The differential inputs of RTIPn
and RRINGn can provide internal matched impedance for E1 75Ω, E1 120Ω, T1
100Ω, or J1 110Ω. The user has the option of turning off internal termination via
the LIU Receive Impedance and Sensitivity Monitor register (
LRISMR).
RRING2 F2
RRING3 L2
RRING4 P2
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 10kΩ ±1%
resistor.