Electrostatic discharge
Almost all modem
components
have
extremely thin conductors
and
metal oxide layers. If these layers are exposed
to
electrostatic dis-
charge
they
will
break
down or perhaps
even
worse, be
damaged
in a
way that inevitably will cause a breakdown later on. The Elec-
tro-Static
Discharge sensitivity
of MOS
and
CMOS
semiconductors
have been known
quite
a while, but nowadays bipolar semiconduc-
tors
and even
precision resistors
are ESD
sensitive.
Consider
there-
fore all
components,
pc-boards and sub-assemblies as
sensitive
to
electrostatic discharge. The text below explains
how
you can mini-
mize
the
risk
of
damage
or
destroying
these devices
by
being
aware
of
the problems,
and
learning
how
to handle these components.
ESD
sensitive options are
packed in
conductive containers
marked
with this symbol.
•
Never open the container unless you are at an ESD pro-
tected work station.
•
Use a wrist
strap
grounded
via
a high
resistance.
•
Use a
grounded work mat
on
your workbench.
•
Never let your dothes come in contact with ESD sensitive
equipment even when you are wearing a grounded wrist
strap.
•
Never touch the component ieads.
•
Never touch open connectors.
•
Use ESD-safe packing materiais.
•
Use the
packing materiai
only once.
•
Keep paper
and nonconductive plastics etc.
away from your
workbench. These may biock the discharge path to ground.
Glossary
A
ASIC Application Specific
Integrated Circuit
C
Calibration Ad- How to restore an
instrument
to
perfonn
in
agreement
justments
with its
specifications
CSA Canadian Safety
Association
safety standard.
G
GaAs A
technique to make
very
fast
ICs using
Gallium Arsenide
substrat.
GPEB General Purpose
Instrumentation Bus used
for
inter-
connecting several
measuring instruments to a com-
mon controller.
I
9
IX-bus An internal address-
and data bus for
commumcation
between microcontroller,
measuring
logic,
and
options.
lEC 1010-1 International Electrical Commission
safety standard.
L
LSI Large Scale
Intergarated
circuit
O
OCXO
Oven Controlled X-tal
Oscillator
P
PCA Printed Circuit Assembly
Performance A procedure
to check
that the
instrument
is
fimction-
Check
ally
operational and
perfonns to
its specification. Must
not require opening of
cabinet.
If
the
instrument
passes
the check it
is
considered as
calibrated.
PWM Pulse
Width
Modulated
U
UCXO Un-Compensated
X-tal Oscillator
(standard)
Electrostatic
discharge
9-3
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