ds2149qt-r Maxim Integrated Products, Inc., ds2149qt-r Datasheet - Page 24

• Manufacturer Part Number: ds2149qt-r
• Description: Ds2149 5v T1/j1 Line Interface Unit
• Manufacturer: Maxim Integrated Products, Inc.

11. NETWORK INTERFACE
Transformer specifications are listed in
resistance necessary for the basic interface and is associated with different transformer turns ratios.
Smaller turns ratios result in lower power-supply requirements. However, series resistance provides
added protection from potentially damaging voltages that can occur during lightning strikes. A basic
network interface is illustrated in
refer to Application Note 324: T1/E1 Network Interface Design.
Table 11-A. Specifications for Receive Transformer
Turns Ratio (all applications)
Primary Inductance
Leakage Inductance
Interwinding Capacitance
Receive Transformer DC Resistance
Table 11-B. Specifications for Transmit Transformer
Turns Ratio, 5V
Primary Inductance
Leakage Inductance
Interwinding Capacitance
Transmit Transformer DC Resistance
Table 11-C. Transformer Turns Ratio vs. Series Resistance
XFMR2
(CR4.1)
0
0
1
1
Primary (Device Side)
Secondary
Primary (Device Side)
Secondary
SPECIFICATION
SPECIFICATION
XFMR1
(CR4.0)
0
1
0
1
OPERATING
VOLTAGE
(V)
5.0
5.0
5.0
5.0
Figure
1:2 ±2%
600mH minimum
1.0mH maximum
40pF maximum
1.0Ω maximum
2.0Ω maximum
600mH minimum
1.0mH maximum
40pF maximum
1.2Ω maximum
1.2Ω maximum
1:1 ±2%
Table 11-A
RECOMMENDED VALUE
RECOMMENDED VALUE
11-1. For a complete discussion of network interface design,
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APPLICATION
Long/Short
Long/Short
Long/Short
Long/Short
and
D4
D4
D4
D4
Table
11-B.
Table 11-C
1:1.15
1:1.15
1:1.6
1:1.6
1:2
1:2
1:2
1:2
1:2
1:2
1:2
1:2
N
illustrates the series
Rt (Ω)
9.1
4:3
4.3
9.1
0
0
0
0
0
0
0
0