12

LT1785/LT1785A

LT1791/LT1791A

©LINEAR TECHNOLOGY CORPORATION 1998

178591f LT/TP 0300 4K • PRINTED IN THE USA

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

LTC485

Low Power RS485 Interface Transceiver

LTC491

Differential Driver and Receiver Pair

LTC1483

Ultralow Power RS485 Low EMI Transceiver

Controlled Driver Slew Rate

LTC1485

Differential Bus Transceiver

10Mbaud Operation

LTC1487

Ultralow Power RS485 with Low EMI, Shutdown and High Input Impedance

Up to 256 Transceivers on the Bus

LTC1520

50Mbps Precision Quad Line Receiver

Channel-to-Channel Skew 400ps (Typ)

LTC1535

Isolated RS485 Full-Duplex Transceiver

LTC1685

52Mbps RS485 Half-Duplex Transceiver

Propagation Delay Skew 500ps (Typ)

LTC1687

52Mbps RS485 Full-Duplex Transceiver

Propagation Delay Skew 500ps (Typ)

4

3

2

1

A

B 7

6

RO

RE

DE

DI

1785/91 F10

RX

TX

120

Ω

120

Ω

LT1785

4

3

2

1

A

B

7

6

RO

RE

DE

DI

RX

TX

LT1785

4

3

2

1

A

B

7

6

RO

RE

DE

DI

4

3

2

1

A

B

7

6

RO

RE

DE

DI

LT1785

LT1785

Figure 10. Half-Duplex RS485 Network Operation

4

3

2

1

A

B 7

8

5

6

RO

RE

DE

DI

RX

TX

1785/91 F11

0.1

µF

300V

47

Ω

1.5KE36CA

47

Ω

CARBON

COMPOSITE

5W

LT1785

RAYCHEM

POLYSWITCH

TR600-150

× 2

Figure 11. RS485 Network with 120V AC Line Fault Protection