Civil Engineering Reference
In-Depth Information
Table 2.1
Environmental conditions, dynamics range and potential ICs test verdicts
Car measurement
methods
Component measurement
methods
IC measurement
methods
Environment
Finalized vehicle
Components, special test board
Special test board
Test verdict
Pretest, release
Pretest, (prerelease),
comparison of semiconductors
Pretest, comparison
of semiconductors
Dynamics range
for comparison
—
Corresponding to transmission
function of measurement
method
Very high, broadband
measurement
Validity range
Corresponding to
the particular car
Corresponding to the
particular constraints of the
component measurement
General
Point of time of
measurement in
the development
process
Only applicable
on availability of
the particular car
Only applicable on
availability of the particular
component or always
applicable on the application
of a dedicated test board
Always
Measurements of the integrated circuit (IC) level can be performed already on
early development samples of the semiconductor. They result in general test ver-
dicts and they are characterized by a high dynamics range. As such, they are very
well suited for comparison of semiconductors from different semiconductor suppli-
ers or for comparison of different sample versions of one specific kind.
Analysis on module level is advantageous, because it can be performed in an
early phase, independent of the vehicle itself. When knowing the correlation be-
tween the applied component measurement method and the car measurement meth-
od, the car manufacturer can evaluate the semiconductor device correspondingly
to the component's requirements. There are some restrictions though, coming from
the partially lower bandwidth noise transmission function of the component mea-
surement method and the dependency of the layout of the components, the applied
passive components and the ground layout.
When performing measurements in cars, typically there is sufficient EMC envi-
ronment available and thus a decision can be taken on the release of the transceiver.
Unfortunately, this kind of measurement can only be performed when the car is
available, which is relatively late in the development process. Furthermore, the in-
formation on EMC capabilities can only be derived for the tested type of vehicle.
Any statement on a noise immunity range margin, which may be required for the
application on another type of car, cannot simply be derived.
A reasonable step-by-step combination of all three levels of measurements re-
sults in an effective process for the development of CAN transceivers with suffi-
cient and even excellent EMC characteristics. The comparison of test results of the
individual levels for transceivers, which have already undergone this test process,
allows the specification of test requirements on IC level, which correlates with the
later stage car constraints. In conjunction with the test specification for CAN trans-
ceivers, an EMC measurement specification for the EMC evaluation on IC level
