DS3695A/DS3695AT/DS3696A

Multipoint RS485/RS422 Transceivers

General Description

The DS3695A and DS3696A are high speed differential

quirements of EIA standard RS485 with extended common

mode range (+12V to −7V), for multipoint data transmission.

In addition they are compatible with requirements of RS-422.

The driver and receiver outputs feature TRI-STATE capabil-

ity. The driver outputs remain in TRI-STATE over the entire

common mode range of +12V to −7V. Bus faults that cause

excessive power dissipation within the device trigger a ther-

mal shutdown circuit, which forces the driver outputs into the

high impedance state. The DS3696A provides an output pin

(TS) which reports the thermal shutdown of the device. TS is

an “open collector” pin with an internal 10 k

Ω pull-up resistor.

This allows the TS outputs of several devices to be wire

OR-ed.

Both AC and DC specifications are guaranteed over the 0˚C

to 70˚C temperature and 4.75V to 5.25V supply voltage

range.

Features

n Meets EIA standard RS485 for multipoint bus

transmission and is compatible with RS-422

n 10 ns driver propagation delays (typical)

n Single +5V supply

ground difference between devices on the bus

n Thermal shutdown protection

n High impedance to bus with driver in TRI-STATE or with

power off, over the entire common mode range allows

the unused devices on the bus to be powered down

n Combined impedance of a driver output and receiver

input is less than one RS485 unit load, allowing up to 32

transceivers on the bus

n 70 mV typical receiver hysteresis

n Available in SOIC packaging

Connection and Logic Diagram

Molded Package, Small Outline (M)

DS005272-1

Top View

DS005272-2

TS was LF (Line Fault) on previous datasheets, TS goes low upon thermal shutdown.

Top View

Order Number DS3695AM, DS3695ATM or DS3696AM

See NS Package Number M08A

February 1996

© 1998 National Semiconductor Corporation

DS005272

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