SPI read issue with AD9204-80EBZ eval board

Hi ManuR,

Here are a few initial questions.

• Do you have jumpers properly placed on J302. These are needed to connect the AD9204 to the SPI bus.
• J301 is on the 3V side of the level shifters U301 and U302. Are your voltage levels appropriate?
• I'm sure you have already looked at this but FYI the AD9204 evaluation board schematic is here: https://www.analog.com/media/en/technical-documentation/evaluation-documentation/AD9204_31_51_58_68_SCH.pdf
• Also, in case you have not seen AN-877, it describes the SPI interface for the AD9204 generation of parts.

Thanks,

Doug

Hi Doug,

thanks for your interest and reply.

* jumpers on j302 are placed (between 1-2, 4-5 and 8-9)
* I also measured the spi signals after the level shifters (on J302) and I see signals as expected (same waveform but different scale)
* I have also looked at the ref documents you sent me, but I believe to follow any reccomandation.

Maybe I am just missing some major steps that I cannot see (the used protocol is wrong, miss of a specfic voltage supply reference somewhere, any other steps to follow after power-up and before the first read... ).

Is there a test which I can try to see if the SPI interface is alive (e.g. writing to an AD register which is supposed to cause some external effects ) ?

Hi ManuR,

If you read Register 0x00, it should come back with a value of 0x18 by default.

One thing I forgot to mention before is the transfer bit. Address 0x08 to Address 0x18 are shadowed. Writes to these addresses do not affect device operation until a transfer command is issued by writing 0x01 to Address 0xFF, setting the transfer bit. Please see the datasheet for more information.

I wonder if this is part of the issue.

Thanks,

Doug

Solved. It was probably crosstalk noise on the SPI master side. thanks

Hi ManuR,

Great Work!

I hope your project goes well.

Doug

Hello manuR,

I have similar problem with my microcontroller , i think its is cross talk noise. could you please elaborate how to detect/solve this problem.

thanks