DS75176B/DS75176BT Multipoint RS-485/RS-422 Transceivers
July 2004
DS75176B/DS75176BT
Multipoint RS-485/RS-422 Transceivers
General Description
The DS75176B is a high speed differential TRI-STATE
®
bus/line transceiver designed to meet the requirements of
EIA standard RS485 with extended common mode range
(+12V to −7V), for multipoint data transmission. In addition, it
is compatible with RS-422.
The driver and receiver outputs feature TRI-STATE capabil-
ity, for the driver outputs over the entire common mode
range of +12V to −7V. Bus contention or fault situations that
cause excessive power dissipation within the device are
handled by a thermal shutdown circuit, which forces the
driver outputs into the high impedance state.
DC specifications are guaranteed over the 0 to 70˚C tem-
perature 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
Small Outline (SO) Package option available for
minimum board space.
n
22 ns driver propagation delays.
n
Single +5V supply.
n
−7V to +12V bus common mode range permits
±
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
Pin out compatible with DS3695/A and SN75176A/B.
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.
Connection and Logic Diagram
00875901
Top View
Order Number DS75176BN, DS75176BTN, DS75176BM or DS75176BTM
See NS Package Number N08E or M08A
TRI-STATE
®
is a registered trademark of National Semiconductor Corp.
© 2004 National Semiconductor Corporation
DS008759
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
