LTC1483

Features:

Low Power: ICC = 120mA Max with Driver Disabled
ICC = 500mA Max with Driver Enabled, No Load
1mA Quiescent Current in Shutdown Mode
Controlled Slew Rate Driver for Reduced EMI
Single 5V Supply
Drivers/Receivers Have ±10kV ESD Protection
7V to 12V Common-Mode Range Permits ±7V 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
Pin Compatible with the LTC485



Application

Battery-Powered RS485/RS422 Applications
Low Power RS485/RS422 Transceiver
Level Translator


Pinout

PIN FUNCTIONS
RO (Pin 1): Receiver Output. If the receiver output is enabled (RE low), then if A > B by 200mV, RO will be high.If A < B by 200mV, then RO will be low.
RE(Pin 2): Receiver Output Enable. A low enables the receiver output, RO. A high input forces the receiver output into a high impedance state.
DE (Pin 3): Driver Outputs Enable. A high on DE enables the driver output. A, B and the chip will function as a line driver. A low input will force the driver outputs into a high impedance state and the chip will function as a line receiver. If RE is high and DE is low, the part will enter a low power (1mA) shutdown state.
DI (Pin 4): Driver Input. If the driver outputs are enabled (DE high) then a low on DI forces the outputs A low and B
high. A high on DI with the driver outputs enabled will force A high and B low.
GND (Pin 5): Ground.
A (Pin 6): Driver Output/Receiver Input.
B (Pin 7): Driver Output/Receiver Input.
VCC (Pin 8): Positive Supply. 4.75V < VCC < 5.25V.

Specifications

Supply Voltage (VCC) ............................................ 12V
Control Input Voltage ................ 0.5V to VCC + 0.5V
Driver Input Voltage .................. 0.5V to VCC + 0.5V
Driver Output Voltage ......................................... ±14V
Receiver Input Voltage ....................................... ±14V
Receiver Output Voltage ............ 0.5V to VCC + 0.5V
Operating Temperature Range
LTC1483C........................................ 0°C £ TA £ 70°C
LTC1483I .................................... 40°C £ TA £ 85°C
Lead Temperature (Soldering, 10 sec)............... 300°C


Description

The LTC®1483 is an ultra-low power differential line transceiver designed for data transmission standard RS485 applications with extended common-mode range ( 7V to 12V). It will also meet the requirements of RS422. The LTC1483 features output drivers with controlled slew rate,decreasing the EMI radiated from the RS485 lines, and improving signal fidelity with misterminated lines. The CMOS design offers significant power savings over its bipolar counterparts without sacrificing ruggedness against overload or ESD damage. Typical quiescent current is only 80mA while operating and less than 1A in shutdown.

The driver and receiver of LTC1483 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. I/O pins are protected against multiple
ESD strikes of over ±10kV.