SN65HVD1785DR UART Interface IC RS-422/RS-485 Interface IC 70-V Fault-Protected RS-485 Transceivers

1 Features

• Bus-Pin Fault Protection to:

• – > ±70 V ('HVD1785, 86, 91, 92)

• – > ±30 V ('HVD1787, 93)

• Common-Mode Voltage Range (–20 V to 25 V) More Than Doubles TIA/EIA 485 Requirement

• Bus I/O Protection

– ±16 kV JEDEC HBM Protection

• Reduced Unit Load for Up to 256 Nodes

• Failsafe Receiver for Open-Circuit, Short-Circuit and Idle-Bus Conditions

• Low Power Consumption

  • – Low Standby Supply Current, 1 μA Typical

  • – ICC 5 mA Quiescent During Operation

• Power-Up, Power-Down Glitch-Free Operation

  
  

2 Applications

• Designed for RS-485 and RS-422 Networks

3 Description

These devices are designed to survive overvoltage faults such as direct shorts to power supplies, mis- wiring faults, connector failures, cable crushes, and tool mis-applications. They are also robust to ESD events, with high levels of protection to human-body model specifications.

These devices combine a differential driver and a differential receiver, which operate from a single power supply. In the 'HVD1785, 'HVD1786, and 'HVD1787, the driver differential outputs and the receiver differential inputs are connected internally to form a bus port suitable for half-duplex (two-wire bus) communication. In the 'HVD1793, the driver differential outputs and the receiver differential inputs are separate pins, to form a bus port suitable for full- duplex (four-wire bus) communication. These ports feature a wide common-mode voltage range, making the devices suitable for multipoint applications over long cable runs. These devices are characterized from –40°C to 105°C.

For similar features with 3.3-V supply operation, see the SN65HVD1781 (SLLS877).

Device Information