AM79C985JC datasheet(31/48 Pages) AMD

31 / 48 page

Am79C985

PRELIMINARY

SYSTEMS APPLICATIONS

eIMR+ to TP Port Connection

The eIMR+ device provides a system solution

to designing non-managed multiport repeaters. The

eIMR+ device connects directly to AC coupling mod-

ules for a 10BASE-T hub. Figure 9 shows the simpli-

ﬁed connection.

Twisted Pair Transmitters

TXD signals need to be properly terminated to meet the

electrical requirement for 10BASE-T transmitters.

Proper termination is shown in Figure 10 which consists

of a 110-

Ω resistor and a 1:1 transformer. The load is a

twisted-pair cable that meets IEEE 802.3, Section 14.4

speciﬁcations. The cable is terminated at the opposite

end by 100

Ω.

Twisted Pair Receivers

RXD signals need to be properly terminated to meet

the electrical requirements for 10BASE-T receivers.

Proper termination is shown in Figure 11. Note that the

receivers do not require external ﬁlter modules.

Figure 9.

Simpliﬁed 10BASE-T Connection

Figure 10.

TXD Termination

110

Ω

100

Ω

110

Ω

100

Ω

110

Ω

100

Ω

110

Ω

100

Ω

TP Connector

eIMR+

TXD0+

TXD0–

RXD0+

RXD0–

TXD1+

TXD1–

RXD1+

RXD1–

TXD2+

TXD2–

RXD2+

RXD2–

TXD3+

TXD3–

RXD3+

RXD3–

RST

CLK

1:1

20651B-14

20651B-15

1:1

Twisted Pair

100

Ω

110

Ω

TXD+

TXD-

20650A-13

AM79C985JC Datasheet(PDF) 31 Page - Advanced Micro Devices

AM79C985JC Datasheet(HTML) 31 Page - Advanced Micro Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Datasheet Download

Link URL