LXT972 Level One, LXT972 Datasheet - Page 33

• Manufacturer Part Number: LXT972
• Description: 3.3V Dual-Speed Fast Ethernet Transceiver Datasheet
• Manufacturer: Level One

Figure 20: Typical Twisted-Pair Interface - Switch
1. Center-tap current may be supplied from 3.3V VCCA as shown. Additional power savings may be
2. The 100 transmit load termination resistor typically required is integrated in the LXT972.
3. Magnetics without a receive pair center-tap do not require a 2 kV termination.
4. RJ-45 connections shown are for a standard switch application. For a standard NIC RJ-45 setup, see
realized by supplying the center-tap from a 2.5V current source. A separate ferrite bead (rated at 50 mA)
should be used to supply center-tap current.
Figure
LXT972
21.
T P O N
V C C A
T P O P
TPIN
TPIP
G N D
0.1 F
270 pF 5%
270 pF 5%
0.1 F
2
50
50
0.01 F
.01 F
1
1:1
1:1
3
*
*
LXT972 Application Information
50
50
* = 0.001 F / 2.0 kV
50
50
50
50
RJ-45
1
2
3
4
5
6
7
8
4
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