10

LTC1686/LTC1687

1686/87 F11a

DRIVER

INPUT

RECEIVER

OUTPUT

10ns/DIV

2V/DIV

2V/DIV

Figure 11a. 100 Feet of Category 5 UTP: 50Mbps

DC and AC attenuation over long distances. Figure 14a

shows a 1

µs pulse propagated down 4000 feet of category

5 UTP. Notice the significant attenuation at the receiver

input and the clean pulse at the receiver output. The DC

attenuation is due to the parasitic resistance of the cable.

Figure 14b shows a 1Mbps square wave over the same

4000 feet of cable.

1686/87 F12

DRIVER

INPUT

RECEIVER

OUTPUT

100ns/DIV

2V/DIV

2V/DIV

Figure 12. 1000 Feet of Category 5 UTP: 4Mbps

1686/87 F13

DRIVER INPUT

DIFFERENTIAL

RECEIVER

INPUT

RECEIVER

OUTPUT

20ns/DIV

2V/DIV

2V/DIV

2V/DIV

1685 F11b

RECEIVER

INPUT

DRIVER

INPUT

RECEIVER

OUTPUT

20ns/DIV

2V/DIV

5V/DIV

2V/DIV

CABLE DELAY

Figure 11b. 100 Feet of Category 5 UTP: 20ns Pulse

Figure 13. 100 Feet of Telephone Grade UTP: 30Mbps

1685 F14a

RECEIVER

INPUT

DRIVER

INPUT

RECEIVER

OUTPUT

1

µs/DIV

1V/DIV

5V/DIV

2V/DIV

CABLE DELAY

Figure 14a. 4000 Feet of Category 5 UTP 1

µs Pulse

1685 F14b

DRIVER

INPUT

RECEIVER

OUTPUT

1

µs/DIV

5V/DIV

2V/DIV

Figure 14b. 4000 Feet of Category 5 UTP 1Mbps Square Wave

1.6Mbps Over 8000 Feet (1.5 Miles)

Category 5 UTP Using Repeaters

The LTC1686/LTC1687 can be used as repeaters to extend

the effective length of a high speed twisted-pair line. Figure

15a shows a three repeater configuration using 2000 feet

segments of category 5 UTP. Figure 15b shows the