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, miswiring

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 fullduplex

(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).