LTC490
Differential Driver and
Receiver Pair
FEATURES
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DESCRIPTIO
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Low Power: I
CC
= 300µA Typical
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 Permit
Live Insertion or Removal of Package
Driver Maintains High Impedance with the
Power Off
Combined Impedance of a Driver Output and
Receiver Allows up to 32 Transceivers on the Bus
70mV Typical Input Hysteresis
28ns Typical Driver Propagation Delays with
5ns Skew
Pin Compatible with the SN75179
The LTC490 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 or ESD damage.
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.
Both AC and DC specifications are guaranteed from 0°C to
70°C and 4.75V to 5.25V supply voltage range.
APPLICATI
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Low Power RS485/RS422 Transceiver
Level Translator
TYPICAL APPLICATI
LTC490
5
D
3
DRIVER
120Ω
6
4000 FT BELDEN 9841
120Ω
8
R
2
RECEIVER
120Ω
7
4000 FT BELDEN 9841
120Ω
DRIVER
D
U
LTC490
RECEIVER
R
LTC490 • TA01
UO
UO
1