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Functional safety isolation

Question asked by froliveira on Nov 12, 2013
Latest reply on Nov 15, 2013 by DaveC

Hi all,


We're developing a functional safety product in accordance with IEC 61508 and ISO 13849.

In our circuit we have a safety-related processor, using an SPI interface to exchange data with a uC non-functional safety.

According with functional safety standards, this SPI communication must be isolated.

By reading ISO 13849-2 (Safety-related parts of control systems), I found some information about opto-isolators (table D.19), which says that optocoupler must be "built in accordance with overvoltage category III according to IEC 60664-1. If a SELV/PELV power supply is used, pollution degree 2 /overvoltage category II applies". But I haven't found any requirements or recommendation to use digital isolators instead.


We have already cataloged ADuM1402 in our database and we desire to use it. Then comes my question: is ADuM140x suitable for functional safety applications? how AD manages the possible faults on digital isolators?


Many thanks in advance!