鈥?/div>
Easily con鏗乬ured in series or in parallel
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 prede鏗乶ed 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 ef鏗乧ient
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 鈥淗鈥?suf鏗亁 coded parts. Refer to the Parts Coding
section for a more in-depth description of these parts.
Siemens Microelectronics, Inc. 鈥?Optoelectronics Division
www.smi.siemens.com/opto/
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October 1998