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Return to Environmental
Stress & Reliability
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Put simply,
this category of testing involves testing a design
up to and sometimes past its electrical
specifications. A common use for such testing is
to get an understanding of design margin (e.g. the
difference between the level where the unit fails
for a given parameter and the level that the
parameter is specified). |
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This
category is very broad. Think of any
electrical
input parameter associated with a given design
that can be varied and you have come up with a
potential test point. Clearly some prioritization
must be employed to ensure that precious testing
resources are not squandered on parameters that
are unlikely to significantly affect the function
of the end device.
Common
parameters that might be tested include, but are
not limited to:
-
Input
Voltage
-
Input
Current
-
Input
Frequency
-
Input
Duty Cycle
-
Input
Waveform Characteristics (such as shape)
-
Safety
testing to explore the effects of intentionally
failing a particular component of the design
while varying an input parameter to further
stress the device.
Note that
it is not just the maximum value that equates to
stress. Minimizing an input may result in a
different stress type and potentially different
failure modes.
Also of
importance is the operating state of the device
under test. In one mode the device may be
insensitive to a particular stress while in
another mode this same stress may cause the device
to fail.
This
category of testing is very dependent upon the
owners knowledge to determine what testing is
most appropriate. Clearly the devices projected
operating environment and knowledge of what
standards it will have to eventually comply with
serve as key sources of guidance for test plan
development.
Test
Specification Template (Electrical Overstress
Testing)
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