LXT971ALC 参数 Datasheet PDF下载

LXT971A 3.3V Dual-Speed Fast Ethernet Transceiver

4.0

4.1

Application Information

Magnetics Information

The LXT971A requires a 1:1 ratio for both the receive and transmit transformers. The transformer

isolation voltage should be rated at 2 kV to protect the circuitry from static voltages across the

connectors and cables. Refer to

for transformer requirements.

A cross-reference list of magnetic manufacturers and part numbers is available in Magnetic

Manufacturers for Networking Product Applications (document number 248991) and is found on

the Intel web site (www.Intel.com). Before committing to a specific component, contact the

manufacturer for current product specifications and validate the magnetics for the specific

application.

Table 15. Magnetics Requirements

Parameter

Min

Nom

Max

Units

Test Condition

Rx turns ratio

Tx turns ratio

Insertion loss

Primary inductance

Transformer isolation

Differential to common mode rejection

–

–

0.0

350

–

40

35

-16

-10

1:1

1:1

0.6

–

1.5

–

–

–

–

–

–

1.1

–

–

–

–

–

–

–

–

dB

µ

H

–

–

–

–

–

.1 to 60 MHz

60 to 100 MHz

30 MHz

80 MHz

kV

dB

dB

dB

dB

Return Loss

4.2

Typical Twisted-Pair Interface

provides a comparison of the RJ-45 connections for NIC and Switch applications in a

typical twisted-pair interface setting.

Table 16. I/O Pin Comparison of NIC and Switch RJ-45 Setups

RJ-45

Symbol

Switch

NIC

TPIP

TPIN

TPOP

TPON

1

2

3

6

3

6

1

2

shows a typical twisted-pair interface with the RJ-45 connections crossed

over for a Switch configuration.

provides a typical twisted-pair interface with

the RJ-45 connections configured for a NIC application.

48

Datasheet

Document #: 249414

Revision #: 002

Rev. Date: August 7, 2002