特性 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

描述 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.