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serial timing of the AD7490

Question asked by Benni3012 on Mar 13, 2015
Latest reply on Mar 19, 2015 by Benni3012


Currently I am working with the AD7490 and trying to get it run with SPI. I am using an USCI-module of an MSP430F5659 to establish the serial communication.

By studying the datasheet of the AD7490 the following question came up:


The AD7490 requests a 16 Bit serial interface timing but with SPI I can only get 8 Bit as a burst. It would be no problem to send two 8 Bit packages but my question is if the AD7490 can handle dead times in the serial timing, which would arise , and if he can, is there a maximum dead time he can handle until he doesn't send any valid data anymore? Currently I am clocking the AD7490 with 16 MHz but still have a dead time of approx. 820 ns between two packages. At the moment i don't know why the dead time between two 8 Bit writes is so much but I am working on that. But when it's mandatory that the AD7490 needs 16 clockcycles without interruption then I don't know how to implement that with SPI, because i would have allways a dead time since there's a microprocessor involved.


Pleas, can anyone help me?


best regards