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Frequently Asked Question

How much isolation can iCoupler products provide?

As of this writing, most iCoupler products carry an isolation rating of either 2.5KVRMS or 5.0KVRMS (the ADuM240x and ADuM225x isolators carry an isolation rating of 5.0KVRMS). The maximum working voltage that iCoupler products support is a function of both the safety approvals a given product has as well as its insulation lifetime as evaluated by testing performed by Analog Devices in addition to that of the safety agencies.

All iCoupler products support working voltages up to 400 VRMS. The ADuM240x and ADuM225x families support higher working voltages.

The maximum working voltage supported by the ADuM240x or ADuM225x depends on the nature of the common-mode waveform that is imposed across the isolation barrier. This is due to the fact that the iCoupler insulation system is stressed differently for the various waveforms shown below. In the case of bipolar AC waveforms, the maximum working voltage is set by the criteria that the insulation have a 50 year minimum lifetime. In the case of other types of voltage waveforms, the maximum working voltage is limited by regulatory safety approvals – despite the insulation's ability to withstand higher voltages with a 50 year minimum lifetime. The table below summarizes the maximum recommended voltages for the ADuM240x and ADuM225x as a function of waveform type:

Parameter Max Constraint
AC Voltage, Bipolar Waveform 400 VRMS (565 (VPK) 50-year minimum lifetime
AC Voltage, Unipolar Waveform 519 VRMS (848 (VPK Maximum CSA/VDE approved working voltage
DC Voltage 848 VPK Maximum CSA/VDE approved working voltage

Table 3: ADuM240x and ADuM225x Maximum Working Voltages

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