ADUM6132_08 AD [Analog Devices], ADUM6132_08 Datasheet - Page 14

• Manufacturer Part Number: ADUM6132_08
• Description: Isolated Half-Bridge Gate Driver with Integrated Isolated High-Side Supply
• Manufacturer: AD [Analog Devices]

ADuM6132
Note that in the presence of strong magnetic fields and high
frequencies, any loops formed by PCB traces may induce
sufficiently large error voltages to trigger the threshold of
succeeding circuitry. Care should be taken in the layout of such
traces to avoid this possibility.
INSULATION LIFETIME
All insulation structures eventually break down when subjected
to voltage stress over a sufficiently long period. The rate of insul-
ation degradation depends on the characteristics of the voltage
waveform applied across the insulation. In addition to the testing
performed by the regulatory agencies, Analog Devices conducts
an extensive set of evaluations to determine the lifetime of the
insulation structure within the ADuM6132.
Analog Devices performs accelerated life testing using voltage
levels higher than the rated continuous working voltage. Accel-
eration factors for several operating conditions are determined.
These factors allow calculation of the time to failure at the actual
working voltage. Table 12 summarizes the recommended peak
working voltages for 50 years and 15 years of service life for
various operating conditions evaluated by Analog Devices. In
many cases, the approved working voltage is higher than the
50-year service life voltage. Operation at these high working
voltages can lead to shortened insulation life in some cases.
The insulation lifetime of the ADuM6132 depends on the
voltage waveform type imposed across the isolation barrier.
The iCoupler insulation structure degrades at different rates
depending on whether the waveform is bipolar ac, unipolar ac,
or dc. Figure 21, Figure 22, and Figure 23 illustrate these
different isolation voltage waveforms.
Bipolar ac voltage is the most stringent environment. The goal
of a 50-year operating lifetime under the bipolar ac condition
determines the maximum working voltage recommended by
Analog Devices.
Table 12. Maximum Continuous Working Voltage
Parameter
AC Voltage, Bipolar Waveform
AC Voltage, Unipolar Waveform
DC Voltage Waveform
1
Refers to continuous voltage magnitude imposed across the isolation barrier. See the Insulation Lifetime section for more details.
Basic Insulation
Basic Insulation
Basic Insulation
Basic Insulation
Peak Voltage
800 V peak
660 V peak
800 V peak
660 V peak
424 V peak
1
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Lifetime
50-year minimum lifetime
15-year minimum lifetime
50-year minimum lifetime
15-year minimum lifetime
50-year minimum lifetime
In the case of unipolar ac or dc voltage, the stress on the
insulation is significantly lower, which allows operation at
higher working voltages while still achieving a 50-year service
life. The working voltages listed in Table 12 can be applied while
maintaining the 50-year minimum lifetime, provided that the
voltage conforms to either the unipolar ac or dc voltage cases.
Any cross-insulation voltage waveform that does not conform to
Figure 22 or Figure 23 should be treated as a bipolar ac waveform,
and its peak voltage should be limited to the 50-year lifetime
voltage value listed in Table 12. Note that the voltage shown in
Figure 22 is sinusoidal for illustration purposes only. It is meant
to represent any voltage waveform varying between 0 V and
some limiting value. The limiting value can be positive or
negative, but the voltage cannot cross 0 V.
RATED PEAK VOLTAGE
RATED PEAK VOLTAGE
RATED PEAK VOLTAGE
0V
0V
0V
Figure 22. Unipolar AC Waveform
Figure 21. Bipolar AC Waveform
Figure 23. DC Waveform