Ethernet Interface - LG FM300 Service Manual

3.1.6 Ethernet Interface (Transformer & RJ-45, U104 & CN101)
This Ethernet Interface is connected to the outside device through the RJ-45 connecter.
And the Ethernet signals from the connecter go into the transformer with the function which is line impedance
matching of Ethernet port.
This transformed impedance required the differential 100ohm for the Main chipset (BCM5358U).
The Ethernet signals go from the transformer to BCM5358U which is the Main chipset.

Ethernet Interface

PORT1_TDP : Plus signal of Ethernet transmit pair.
PORT1_TDN : Minus signal of Ethernet transmit pair.
PORT1_RDP : Plus signal of Ethernet receive pair.
PORT1_RDN : Minus signal of Ethernet receive pair.
R133
PORT1_TDP
R135
PORT1_TDN
PORT1_RDP
PORT1_RDN
LGE Internal Use Only
VDD_2.5
0
FB100
0
R137 0
R138 0
C153 C152 C151 C154 C128 C129 C130
8.2p 8.2p 8.2p 8.2p 0.1u 10u 10u
P1_RDP
P1_RDN
P1_TDP
C137 1n
P1_TDN
C138 1n
Figure 3.6 Transformer & RJ-45
1
TD+ TX-
2
220
V_CTR1 CM2
3
TD- TX+
6
RD+ RX+
7
U104
V_CTR2 CM1
8
RD- RX-
4
NC1 NC4
5
NC2 NC3
ELCP0009412
TLA-6T118LF
C131 C132
0.1u 0.1u
CN101
G1 G3
9
1
3
R146 75
5
7
R148 75
G2 G4
10
ENZY0030801
85507-5001
- 17 - Copyright © 011 LG Electronics. Inc. All right reserved.
3. TECHNICAL BRIEF
3. TECHNICAL BRIEF
14
P1_TDN
15 C127 1n
R134 75
16
P1_TDP
11
P1_RDP
10
9
P1_RDN
13
12
2
4
6
8
Only for training and service purposes