DS21455 Maxim Integrated Products, DS21455 Datasheet - Page 158

• Manufacturer Part Number: DS21455
• Description: Network Controller & Processor ICs Quad E1-T1-J1 Single -Chip Transceiver (S
• Manufacturer: Maxim Integrated Products

Specifications of DS21455

• Product: Framer
• Number Of Transceivers: 4
• Data Rate: 64 Kbps
• Supply Voltage (max): 3.465 V
• Supply Voltage (min): 3.135 V
• Supply Current (max): 328 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Package / Case: BGA

25. LINE INTERFACE UNIT (LIU)
The LIU in the DS21455/DS21458 contains three sections: the receiver, which handles clock and data
recovery; the transmitter, which wave-shapes and drives the network line; and the jitter attenuator. These
three sections are controlled by the line interface control registers (LIC1–LIC4), which are described
below. The LIU has its own T1/E1 mode select bit and can operate independently of the framer function.
The DS21455/DS21458 can switch between T1 or E1 networks without changing any external
components on either the transmit or receive side.
unbalanced network connections using minimal components. In this configuration the device can connect
to T1, J1, or E1 (75Ω or 120Ω) without any component change. The receiver can adjust the 120Ω
termination to 100Ω or 75Ω. The transmitter can adjust its output impedance to provide high return loss
characteristics for 120Ω, 100Ω, and 75Ω lines. Other components may be added to this configuration in
order to meet safety and network protection requirements. This is covered in Section
Circuits).
Figure 25-1. Basic Balanced Network Connections
Rx
Tx
60 Ω *
0.047 µ F
0.01 µ F
158 of 270
60 Ω *
Figure 25-1
TTIP
TRING
RTIP
RRING
*USE 60Ω WHEN USING INTERNAL TERMINATION FEATURE.
DS21455/
DS21458
and
Figure 25-2
show basic balanced and
25.8
(Recommended