DS26521LN+ Maxim Integrated Products, DS26521LN+ Datasheet - Page 77

• 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

8.11.5 LIU Loopbacks
The DS26521 provides four LIU loopbacks for diagnostic purposes: analog loopback, local loopback, remote
loopback, and dual loopback. In the loopback diagrams that follow, TSER, TCLK, RSER, and RCLK are
inputs/outputs from the framer.
8.11.5.1
The analog output of the transmitter TTIP and TRING is looped back to RTIP and RRING of the receiver. Data at
RTIP and RRING is ignored in analog loopback. This is shown in
Figure 8-22. Analog Loopback
8.11.5.2
The transmit system data (the internal signals TTIP, TRING, and TCLK) is looped back to receive-side inputs to the
receive jitter attenuator. The data is also output on TTIP and TRING. Signals at RTIP and RRING are ignored. This
loopback is conceptually shown in
Figure 8-23. Local Loopback
TSER
TCLK
RSER
RCLK
TCLK
TSER
RCLK
RSER
TRANSMIT
RECEIVE
FRAMER
FRAMER
Analog Loopback
Local Loopback
TRANSMIT
FRAMER
RECEIVE
FRAMER
ATTENUATOR
ATTENUATOR
OPTIONAL
OPTIONAL
JITTER
JITTER
Figure
ATTENUATOR
ATTENUATOR
OPTIONAL
OPTIONAL
JITTER
JITTER
8-23.
TRANSMIT
DIGITAL
77 of 258
RECEIVE
DIGITAL
TRANSMIT
DIGITAL
RECEIVE
DIGITAL
TRANSMIT
ANALOG
TRANSMIT
RECEIVE
ANALOG
RECEIVE
ANALOG
ANALOG
Figure
8-22.
DS26521 Single T1/E1/J1 Transceiver
LINE
DRIVER
LINE
DRIVER
RRING
RTIP
TRING
TTIP
RTIP
RRING