Features
 High-CAB-Loading driving ability
 Polarity Free for RS485 bus pins
 Integrated TVS Protection for Bus Terminals :
±15 kV IEC 61000-4-2, Contact Discharge
±20 kV IEC 61000-4-2, Air-Gap Discharge
 HBM/MM ±8kV / ±800V ESD Specification for
all pins
 Meet the Requirements of the EIA/TIA-485
Standards with 5V Power Supply
 Data Rate up to 10Mbps
 Hot-Swap Glitch free Protection on Control
Inputs
 Up to 256 Transceivers on the Bus
Applications
 Energy Meter Networks
 Motor Control
 Industrial Control
 Telecommunications Equipment
 Security System
Description
The AZRS5485E is a High-CAB-Loading driving
and Polarity-Free half-duplex RS485 transceiver
IC with ±15kV IEC 61000-4-2 contact discharge
protection. This device is fully compliant with the
EIA/TIA-485 standard with 5V power supply.
For the Polarity-free function, the AZRS5485E
can automatically detect the polarity for A and B
pins when “pull-high” for A and “pull-low” for B
have been designed on the RS485 bus. The
polarity detection function will be enabled when
the AZRS5485E has been power up to 5V.
The detection function real-time monitors the bus
polarity without any data flow on the RS485 bus.
AZRS5485E is slave-type RS485 to feature the
Polarity-Free function, which does not design the
pull-up and pull-down resistor on the slave
device.
For the High-CAB-Loading condition, there are
capacitors between bus A and bus B when long
bus condition or protected device connected.
AZRS5485E can enhance the bus voltage
quickly to balance the voltage of bus A and bus B
so that they can transmit the data on the long
cable length under the same application.
The AZRS5485E has the thermal shutdown and
the current limited function in the transmitter to
protect the device from damage by system fault
conditions during normal operating condition.
AZRS5485E is designed 1/8 unit load with
minimum 96kΩ of input impedance, which can
connect 256 devices on a bus at least.