Intel 21143 manual Ready Designs, Minimum Components Required for 10BASE-T, Design Guide

Intel® 21143 PCI/CardBus 10/100Mb/s Ethernet LAN Controller

Figure 5 shows the minimum component requirement for the 10BASE-T network connection. This implementation uses a filter transformer module with a 1:2 transformer on the transmit path to compensate for the voltage swing. The required components for this configuration are as follows:

•Terminating and decoupling components

•Filter, transformer, and common-mode chokes

	•	RJ45 connector
Figure 5. Minimum Components Required for 10BASE-T
		21143
		tp_td+ 6	27 Ω
		tp_td++ 7	140 Ω	TP Filters
				and Chokes
		Transmit	510 Ω	78Z1122 or
		Path		FD22-114G
		tp_td- 5	27 Ω	(SMD)
		tp_td-- 4	140 Ω	RJ45
				1
				2
				3
		tp_rd- 9		6
			49.9 Ω
		Receive
		Path	49.9 Ω
		tp_rd- 10		GND
			0.01 ∝ F	0.1 ∝ F
			GND	GND
				LJ-05143.WMF
3.2	100-Ready Designs

The 21143 can also be designed for systems that are “100-Ready.” The term “100-Ready” implies a system that has a 10 Mb/s network that can easily be upgraded to become a 10/100 Mb/s network. There are two methods for providing 100-Ready designs:

•Provide a connector for an internal optional daughtercard.

•Provide an MII connector for an external module that connects to the MII/SYM port.

These two methods are described in Table 6.

12 Design Guide