LTC1485
Differential Bus Transceiver
FEATURES
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DESCRIPTIO
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ESD Protection over
±
10kV
Low Power: I
CC
= 1.8mA Typ
28ns Typical Driver Propagation Delays with
4ns Skew
Designed for RS485 or RS422 Applications
Single 5V Supply
– 7V to 12V Bus Common-Mode Range Permits
±7V
Ground Difference Between Devices on the Bus
Thermal Shutdown Protection
Power-Up/Down Glitch-Free Driver Outputs
Driver Maintains High Impedance in Three-State or
with the Power Off
Combined Impedance of a Driver Output and
Receiver Allows up to 32 Transceivers on the Bus
60mV Typical Input Hysteresis
Pin Compatible with the SN75176A, DS75176A, and
SN75LBC176
The LTC
®
1485 is a low power differential bus/line trans-
ceiver designed for multipoint data transmission standard
RS485 applications with extended common-mode range
(12V to – 7V). It also meets the requirements of RS422.
The CMOS with Schottky design offers significant power
savings over its bipolar counterpart without sacrificing
ruggedness against overload or ESD damage.
The driver and receiver feature three-state outputs, with
the driver outputs maintaining high impedance over the
entire common-mode range. Excessive power dissipation
caused by bus contention or faults is prevented by a
thermal shutdown circuit which forces the driver outputs
into a high impedance state. I/O pins are protected against
multiple ESD strikes of over
±10kV.
The receiver has a fail-safe feature which guarantees a
high output state when the inputs are left open.
Both AC and DC specifications are guaranteed from – 40°C
to 85°C and 4.75V to 5.25V supply voltage range.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATI
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S
Low Power RS485/RS422 Transceiver
Level Translator
TYPICAL APPLICATI
DE
3
5V
8
LTC1485
6
6
120Ω
7
5V
8
LTC1485
DI
4
DRIVER
120Ω
7
4000 FT 24 GAUGE TWISTED PAIR
RO
1
RECEIVER
2
RE
5
5
U
DE
3
DRIVER
4
DI
RECEIVER
1
RO
2
RE
1485 TA01
UO
UO
1
LINER [ LINEAR TECHNOLOGY ]
