UTRS458

DESCRIPTION 

The UTC UTRS458 is a Polarity-Free half-duplex transceiver 

designed for RS-485 data bus network, which contains one transmitter 

and one receiver. The UTC UTRS458 features a fail-safe receiver, 

which guarantees the receiver to output high when the receiver inputs 

are open, short or idle. 

The UTC UTRS458 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 detection function is real-time monitored the bus 

polarity without any data flow on the RS485 bus. 

The UTC UTRS458 also features a hot-swap glitch free protection 

circuits which guarantee outputs of both the transmitter and the 

receiver in a high impedance state during the power up period. So that 

the large short current from power to ground will be disable by glitch 

free function, which will save the power and enhance the efficiency of 

the power up. 

The UTC UTRS458 is optimized for signal rates up to 500Kbps 

with differential voltage of 2.3V. The UTC UTRS458 also has the 

thermal shutdown function when the temperature is over 150°C and 

the protection of the current limitation in the transmitter to protect the 

itself from the damage by the system-fault conditions during normal 

operation.

FEATURES

* Meet the requirements of the EIA/TIA-485 standards. 

* 5.0V single power supply. 

* 1µA low-current shutdown mode. 

* HBM ±12kV ESD protection for Transmitter Output 

* True fail-safe receiver while maintaining EIA/TIA-485 

compatibility. 

* Hot-swap glitch free protection on control inputs. 

* Up to 256 transceivers on the bus. 

* Maximum baud rate up to 500Kbps. 

* Transmitter short circuit current limit. 

* Thermal shutdown for overload protection. 

* Polarity-Free for RS485 bus pins. 

规格书UTRS458