FEATURES

W)

mV)

BENEFITS

repeated faults without damage

such as salt, dirt, and humidity

for increased voltage or current

DESCRIPTION

Siemens Solid State Relays (SSRs) are miniature, optically-coupled relays

with high-voltage MOSFET outputs. The relays are capable of switching ac

or dc loads from as little as nanovolts to hundreds of volts. Likewise, the

relays can switch currents in the range of nanoamps to hundreds of milli-

amps. The MOSFET switches are ideal for small signal switching and are

primarily suited for dc or audio frequency applications.

Siemens offers integrated current limiting on many of its relays. If load

current through the relay exceeds the rated value, the relay clamps the

current at a predefined value. If the excessive load current persists, the

limiting circuit has a foldback feature to minimize relay power dissipation.

The current-limit circuit has a multitude of uses. It can be used in tele-

phony to clamp excessive currents emanating from lightning strikes and/

or power-main crosses or in instrumentation and industrial application to

squelch transients from reactive loads. The current-limit circuit also

provides short-circuit protection in power-feed applications.

The SSRs feature a monolithic output die that minimizes wire bonds and

permits easy integration of high-performance circuits such as current

limiting in normally-open switches. The output die contains all the neces-

sary circuitry to perform a relay function, including the photodiode

receptor array, turn-on and turn-off control circuitry, and the MOSFET

switches. The optically-coupled input is controlled by a highly efficient

GaAlAs infrared LED.

Siemens SSRs are available in a 6- or 8-pin through-hole DIP or in gull-

wing surface-mount packages. Some parts are also offered in 8- or 18-pin

small-outline packages (SOPs). The SOPs are size and height compatible

with PCMCIA Type 2 cards. A 0.4 mm distance through insulation spacing

is also available on “H” suffix coded parts. Refer to the Parts Coding

section for a more in-depth description of these parts.

High Voltage Solid State Relays

General Information

Siemens Microelectronics, Inc. • Optoelectronics Division

www.smi.siemens.com/opto/

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October 1998