AnsweredAssumed Answered

ADUM1401, ADUM5402, SPI, "three state"

Question asked by Tommaso on Feb 29, 2012
Latest reply on Feb 29, 2012 by MSCantrell


I would like to ask the following question about ADUM1401C and ADUM5402C.

I would use ADUM1401C and ADUM5402C to interface to an SPI bus a section of a circuit which has to be isolated. On the SPI bus are connected also other two devices.

So, how is it possible to get in "three state" the outputs of ADUM so that other devices can transmit over the bus without collisions?

I thought to obtain the objective by powering off ADUM's SPI side when other devices have to use the bus, but I'm not sure it could be a good solution since AN-825 consider this power state as "special condition" and the time between the supply is on and the ADUM can work as specified con be an issue. (Is this time known?)


Thanks a lot for the help.