DS26521LN+ Maxim Integrated Products, DS26521LN+ Datasheet - Page 70

• Manufacturer Part Number: DS26521LN+
• Description: IC TXRX T1/E1/J1 64-LQFP
• Manufacturer: Maxim Integrated Products
• Type: Line Interface Units (LIUs)r

Specifications of DS26521LN+

• Number Of Drivers/receivers: 1/1
• Protocol: T1/E1/J1
• Voltage - Supply: 3.135 V ~ 3.465 V
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.11.2 Transmitter
NRZ data arrives from the framer transmitter; the data is encoded with HDB3 or B8ZS or AMI. The encoded data
passes through a jitter attenuator if it is enabled for the transmit path. A digital sequencer and DAC are used to
generate transmit waveforms complaint with T1.102 and G.703 pulse templates.
A line driver is used to drive an internal matched impedance circuit for provision of 75Ω, 100Ω, 110Ω, and 120Ω
terminations. The transmitter couples to the E1 or T1 transmit twisted pair (or coaxial cable in some E1
applications) via a 1:2 step-up transformer. For the device to create the proper waveforms, the transformer used
must meet the specifications listed in
1.544MHz for T1/J1 operation.
The DS26521 drivers have a short-circuit and open-circuit detection driver-fail monitor. The TXENABLE pin can
high impedance the transmitter outputs for protection switching. The individual transmitters can also be placed in
high impedance through register settings. The DS26521 also has functionality for powering down the transmitters
individually. The relevant telecommunications specification compliance is shown in
Table 8-31. Telecommunications Specification Compliance for DS26521 Transmitters
Table 8-32. Transformer Specifications
Turns Ratio 3.3V Applications
Primary Inductance
Leakage Inductance
Intertwining Capacitance
Transmit Transformer DC
Resistance
Receive Transformer DC
Resistance
Transmit Electrical Characteristics for E1 Transmission
T1 Telecom Pulse Template Compliance
T1 Telecom Pulse Template Compliance
and Return Loss Compliance
TRANSMITTER FUNCTION
SPECIFICATION
Primary (Device Side)
Secondary
Primary (Device Side)
Secondary
Table
8-32. The transmitter requires a transmit clock of 2.048MHz for E1 or
70 of 258
TELECOMMUNICATIONS COMPLIANCE
1:1 (receive) and 1:2 (transmit) ±2%
RECOMMENDED VALUE
DS26521 Single T1/E1/J1 Transceiver
600μH minimum
1.0μH maximum
40pF maximum
1.0Ω maximum
2.0Ω maximum
1.2Ω maximum
1.2Ω maximum
ANSI T1.403
ANSI T1.102
ITU-T G.703
Table
8-31.