1 Features

• Meets or exceeds the requirements of the TIA/

EIA-485A and TIA/EIA-422B standards

• Total ionizing dose (TID) characterized up to

30krad (Si)

– Total ionizing dose radiation lot acceptance

testing (TID RLAT) for every wafer lot to 30krad

(Si)

• Single-event effects (SEE) characterized

– Single event latch-up (SEL) immune to linear

energy transfer (LET) = 43MeV⋅cm2 /mg at

125°C

• Space enhanced plastic (Space EP)

– Controlled baseline

– One assembly and test site

– One fabrication site

– Gold bond wire

– NiPdAu lead finish

– Military temp range (-55°C to 125°C)

– Extended product life cycle

– Product traceability

– Meets the NASA ASTM E595 outgassing

specification

• 3V to 5.5V supply voltage

• 1.65V to 5.5V Supply for data and enable signals

• SLR Pin Selectable Data Rates:

– 20Mbps and 50Mbps

• Bus I/O protection

– ±70V DC bus fault

– ±16kV HBM ESD

– ±8kV IEC 61000-4-2 contact discharge

– ±4kV IEC 61000-4-4 fast transient burst

• Symmetric common mode range: ±12V

• Enhanced receiver hysteresis for noise immunity

• Glitch-free power-up or down for hot plug-in

capability

• Open, short, and idle bus failsafe

• 1/8 unit load (up to 256 bus nodes)

• Leaded 14-pin SOIC package

2 Applications

• Low Earth Orbit (LEO) Space Applications

• Command & data handling

• Communications payload systems

• Optical imaging

• Radar imaging payload

3 Description

THVD9491-SEP is a space enhanced, ±70V faultprotected

full-duplex RS-422/RS-485 transceiver

using a 1.65V to 5.5V logic supply for data and enable

logic signals, and a 3V to 5.5V bus side supply. The

device has a slew rate select feature that enables the

use at two maximum speeds based on the SLR pin

setting.

The device features integrated IEC ESD protection,

eliminating the need for external system-level

protection components. The ±12V input commonmode

range makes reliable data communication over

longer cable run lengths and/or in the presence

of large ground loop voltages. Enhanced 250mV

receiver hysteresis provides high noise rejection. In

addition, the receiver fail-safe feature makes sure of

a logic high when the inputs are open or shorted

together.

THVD9491-SEP device is available in a standard

14-pin SOIC package.