DS3695A/DS3695AT/DS3696A Multipoint RS485/RS422 Transceivers
February 1996
DS3695A/DS3695AT/DS3696A
Multipoint RS485/RS422 Transceivers
General Description
The DS3695A and DS3696A are high speed differential
TRI-STATE
廬
bus/line transceivers designed to meet the re-
quirements of EIA standard RS485 with extended common
mode range (+12V to 鈭?V), 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 鈭?V. 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 鈥渙pen collector鈥?pin with an internal 10 k鈩?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藲C
to 70藲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
n
鈭?V to +12V bus common mode range permits
鹵
7V
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
TRI-STATE
廬
is a registered trademark of National Semiconductor Corporation.
漏 1998 National Semiconductor Corporation
DS005272
www.national.com
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