adum1311 Analog Devices, Inc., adum1311 Datasheet - Page 20

• Manufacturer Part Number: adum1311
• Description: Triple-channel Digital Isolators
• Manufacturer: Analog Devices, Inc.

ADuM1310/ADuM1311
approved working voltages. In many cases, the approved
working voltage is higher than 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 ADuM131x 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 17, Figure 18, and Figure 19 illustrate these
different isolation voltage waveforms.
Bipolar ac voltage is the most stringent environment. The goal
of a 50-year operating lifetime under the ac bipolar condition
determines the Analog Devices recommended maximum
working voltage.
In the case of unipolar ac or dc voltage, the stress on the
insulation is significantly lower. This allows operation at higher
working voltages while still achieving a 50-year service life. The
working voltages listed in Table 10 can be applied while
maintaining the 50-year minimum lifetime provided the voltage
conforms to either the unipolar ac or dc voltage case. Any cross-
insulation voltage waveform that does not conform to Figure 18
or Figure 19 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 10.
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Note that the voltage presented in Figure 18 is shown as
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 18. Unipolar AC Waveform
Figure 17. Bipolar AC Waveform
Figure 19. DC Waveform