1

LTC1320

DESCRIPTIO

S

FEATURE

AppleTalk

s

Single Chip Provides Complete

LocalTalk

s

s

s

Drivers Maintain High Impedance in Three-State

or with Power Off

s

30ns Driver Propagation Delay Typ

s

5ns Driver Skew Typ

s

Thermal Shutdown Protection

s

Drivers are Short-Circuit Protected

The LTC1320 is an RS422/RS562 line transceiver de-

signed to operate on LocalTalk networks. It provides one

differential RS422 driver, one single-ended RS562 driver,

two single-ended RS562 receivers, and one differential

RS422 receiver. The LTC1320 draws only 1.2mA quies-

cent current when active and 30

µA in shutdown, making

it ideal for use in battery-powered devices and other

systems where power consumption is a primary concern.

The LTC1320 drivers are specified to drive

±2V into 100Ω.

Additionally, the driver outputs three-state when disabled,

during shutdown, or when the power is off; they maintain

high impedance even with output common-mode volt-

ages beyond the power supply rails. Both the driver

outputs and receiver inputs are protected against ESD

damage to beyond 5kV.

The LTC1320 is available in the 18-pin SOL package.

S

APPLICATI

s

LocalTalk Peripherals

s

Notebook/Palmtop Computers

s

Battery-Powered Systems

Typical LocalTalk Connection

Output Waveforms

2V/DIV

2V/DIV

5V/DIV

5V/DIV

DATA IN

SIGNALS

ON LINE

DATA OUT

(REMOTE

RECEIVER)

50ns/DIV

APPLICATI

TYPICAL

17 22Ω

100pF

22

Ω

16 22Ω

22

Ω

11

10

1

3

8

18

5V

–5V

914

LTC1320

#1

LTC1320 • TA01

100pF

120

Ω

LocalTalk

TRANSFORMER

DATA IN

5

4

22

Ω

22

Ω

22

Ω

100pF

22

Ω

100pF

1k

1k

DATA OUT

SHUTDOWN

TX ENABLE

RX ENABLE

AppleTalk and LocalTalk are registered trademarks of Apple Computer, Inc.