I/O Controller Hub 2
R
Intel
®
Pentium
®
4 Processor / Intel
®
850 Chipset Family Platform Design Guide 173
9.9.3.4 Phoneline HPNA Termination
The transmit/receive differential signal pair is terminated with a pair of 51.1Ω (1%) resistors. This
parallel termination should be placed close to the 82562EH. The center, common point between
the 51.1 Ω resistors is connected to a pair of 806 Ω resistors and a single 0.022 µF capacitor. The
opposite end of one 806 Ω resistor is tied to VCCA (3.3 V), and the opposite end of the other
806 Ω resistor and the capacitor are connected to ground. The termination is shown in Figure 123.
Figure 123. Intel
®
82562 EH Termination
1
2
3
4
5
6
TabTab
1
2
3
4
5
6
TabTab
8
Phone / modem
Shield ground
Line
8
7
7
LAN_82562EH_term
1500 pF 1500 pF
6.8 µH
6.8 µH
6.8 µH 6.8 µH
0
T
10
9
1
2
3
B6008
rx_tx_p
rx_tx_n
0.022 µF
51.1 Ω
51.1 Ω
806 Ω
806 Ω
A+3.3 V
Tip
Ring
The filter and magnetics component T1, integrates the required filter network, high-voltage
impulse protection, and transformer to support the HomePNA* LAN interface.
One RJ-11 jack (labeled “LINE” in Figure 123) allows the node to be connected to the phoneline,
and the second jack (labeled “PHONE” in Figure 123) allows other downline devices to be
connected at the same time. The second connector is not required by the HomePNA. However,
typical PCI adapters and PC motherboard implementations are likely to include it for user
convenience.
A low-pass filter, setup in-line with the second RJ-11 jack is also recommended by the
HomePNA* to minimize interference between the HomeRun connection and a POTs voice or
modem connection on the second jack. This places a restriction of the type of devices connected to
the second jack as the pass-band of this filter is set approximately at 1.1 MHz. Refer to the
HomePNA* website: www.homepna.org
for up-to-date information and recommendations
regarding the use of this low-pass filter to meet HomePNA* certifications.
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