Datasheet

1
LTC485
Low Power RS485
Interface Transceiver
S
F
EA
T
U
RE
D
U
ESCRIPTIO
The LTC485 is a low power differential bus/line transceiver
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 design offers significant power savings over its
bipolar counterpart without sacrificing ruggedness against
overload of 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.
The receiver has a fail-safe feature which guarantees a
high output state when the inputs are left open.
The LTC485 is fully specified over the commercial and
extended industrial temperature range.
Low Power: I
CC
= 300µA Typ
Designed for RS485 Interface 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
Permit Live Insertion or Removal of Transceiver
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
70mV Typical Input Hysteresis
30ns Typical Driver Propagation Delays
with 5ns Skew
Pin Compatible with the SN75176A, DS75176A
and µA96176
Low Power RS485/RS422 Transceiver
Level Translator
U
S
A
O
PP
L
IC
AT
I
U
A
O
PP
L
IC
AT
ITY
P
I
CA
L
V
CC1
GND1
R
RO1
RE1
DE1
DI1
D
V
CC2
GND2
R
RO2
RE2
DE2
DI2
D
Rt
Rt
LTC485 • TA01
Driver Outputs
A
B
LTC485 • TA02

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