AM79C975VCW datasheet(86/304 Pages) AMD

86 / 304 page

Am79C973/Am79C975

P R E L I M INARY

Figure 37. TX± and RX± Termination

10BASE-T Block

The 10BASE-T block consists of the following sub-

blocks:

— Transmit Process

— Receive Process

— Interface Status

— Collision Detect Function

— Jabber Function

— Reverse Polarity Detect

Refer to Figure 38 for the 10BASE-T block diagram.

Twisted Pair Transmit Function

Data transmission over the 10BASE-T medium re-

quires use of the integrated 10BASE-T MAU and uses

the differential driver circuitry on the TX± pins.

TX± is a differential twisted-pair driver. When properly

terminated, TX± will meet the transmitter electrical re-

quirements for 10BASE-T transmitters as specified in

IEEE 802.3, Section 14.3.1.2. The load is a twisted pair

cable that meets IEEE 802.3, Section 14.4.

The TX± signal is filtered on the chip to reduce har-

monic content per Section 14.3.2.1 (10BASE-T). Since

filtering is performed in silicon, TX± can be connected

directly to a standard transformer. External filtering

modules are not needed.

Twisted Pair Receive Function

The RX+ port is a differential twisted-pair receiver.

When properly terminated, the RX+ port will meet the

electrical requirements for 10BASE-T receivers as

specified in IEEE 802.3, Section 14.3.1.3. The receiver

has internal filtering and does not require external filter

modules or common mode chokes.

Signals appearing at the RX± differential input pair are

routed to the internal decoder. The receiver function

meets the propagation delays and jitter requirements

specified by the 10BASE-T Standard. The receiver

squelch level drops to half its threshold value after un-

squelch to allow reception of minimum amplitude sig-

RX+

RX–

SDI+

SDI–

TX+

TX–

3.3 V

RX+ (3)

TX+ (1)

RX– (6)

TX– (2)

RJ45

Connector

Isolation

Transformer with

common-mode

chokes

Ω

2 K

Ω

1 K

Ω

.01 µF

0.001 µF

2KV

Ω

1:1.414

1:1 *

(8)

(7)

(5)

(4)

(chassis ground)

21510D-42

Notes:

1. The isolation transformers include common-mode chokes.

2. Consult magnetics vendors for appropriate termination schemes.

49.9

Ω, 1%

49.9

Ω, 1%

0.1

µF

49.9

Ω, 1%

AM79C975VCW Datasheet(PDF) 86 Page - Advanced Micro Devices

AM79C975VCW Datasheet(HTML) 86 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 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL