5

LTC490

Figure 4. Receiver Propagation Delays

Figure 3. Driver Propagation Delays

TI E WAVEFOR

S

G

WITCHI

S

S

APPLICATI

I FOR ATIO

Typical Application

A typical connection of the LTC490 is shown in Figure 5.

Two twisted-pair wires connect two driver/receiver pairs

for full duplex data transmission. Note that the driver and

receiver outputs are always enabled. If the outputs must be

disabled, use the LTC491.

There are no restrictions on where the chips are con-

nected, and it isn’t necessary to have the chips connected

at the ends of the wire. However, the wires must be

terminated only at the ends with a resistor equal to their

characteristic impedance, typically 120

Ω. Because only

Figure 5. Typical Connection

LTC490 • TA06

120

Ω

120

Ω

SHIELD

LTC490

DRIVER

RECEIVER

LTC490

DRIVER

DX

RX

DX

RX

2

3

5

6

7

8

RECEIVER

+

0.01

µF

1

4

5V

SHIELD

8

7

6

5

+

0.01

µF

5V

4

2

3

1

LTC490 • TA05

A-B

0V

0V

OUTPUT

1.5V

1.5V

INPUT

R

LTC490 • TA04

D

3V

0V

1.5V

1.5V

80%

20%

50%

10%

Z

Y

90%

50%