DESCRIPTION
The LTC1481 is an ultralow power differential line trans-
ceiver designed for data transmission standard RS485
applications. It will also meet the requirements of RS422.
The CMOS design offers significant power savings over its
bipolar counterparts without sacrificing ruggedness against
overload or ESD damage. Typical quiescent current is only
80µA while operating and less than 1µA in shutdown.
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 LTC1481 is fully specified over the commercial and
extended industrial temperature range and is available in
8-pin PDIP and SO packages.
FEATURES
Low Power: I= 120µA Max with Driver Disabled
Drivers/Receivers Have ±10kV ESD Protection
1µA Quiescent Current in Shutdown Mode
High Speed: Up to 2.5Mbits/s Data Rate
ICC= 500µA Max with Driver Enabled, No Load
Single 5V Supply
－7V to 12V Common Mode Range Permits
Ground Difference Between Devices on the Data Line
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
Up to 32 Transceivers on the Bus
30ns Typical Driver Propagation Delays
with 5ns Skew
Pin Compatible with the LTC485
APPLICATIONS
Battery-Powered RS485/RS422 Applications
Low Power RS485/RS422 Transceiver
Level Translator
TYPICAL APPLICATION
Supply Current vs Temperature
TEST CIRCUITS
Driver DC Test Load
Receiver Timing Test Load
Driver/Receiver Timing Test Circuit
Driver Timing Test Load
P/N Package
LTC486 SMD
LTC1485 DIP-8