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AD5672R Daisy chain not working

Hello

I'm currently working on daisy chaining 2 AD5672R DACs together, I've sent in the command(1000 and DB0=1) to enable the daisy chain mode but it doesn't seem to be responding to the command. I've attached a snap of the chipscope signals and i believe it is what is recommended on the datasheet. The first 8 writes are for the first AD5672R and the secnond 8(longer writes) are for the second AD5672R. could you please advice me on the normal process for daisy chaining these DACS. Also not seen in the pics is the LDAC is held low for the duration of the run any help would be great.

Thank you 

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  • Hi,

    Based on the waveforms you provided, DAC_2 will not enter into Daisy Chain mode but we expect it to process the command it receives. 

    Using pic5 you posted, I divided the stream of data into frames, frame 1 consists of only 24 clk cycles but frames 2,3,4... consists of 48 clk cycles each. As you can see, the first 24 bits (of frame 2,3,4) are really intended for DAC_2, and the second 24 bits are for DAC_1. We can also see that DAC_2 doesn't really process anything since it is sending NO OPERATION command (and all 24 bits are zero).

    As for pic3, can you share what was the 24 bit content for DAC_2? Kindly make sure to toggle /SYNC after the 48-bit frame is sent and set it low again before the next frame. I would also appreciate if you can also share the /SYNC and /LDAC  signals.

    Cheers,

    Ivan

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  • Hi,

    Based on the waveforms you provided, DAC_2 will not enter into Daisy Chain mode but we expect it to process the command it receives. 

    Using pic5 you posted, I divided the stream of data into frames, frame 1 consists of only 24 clk cycles but frames 2,3,4... consists of 48 clk cycles each. As you can see, the first 24 bits (of frame 2,3,4) are really intended for DAC_2, and the second 24 bits are for DAC_1. We can also see that DAC_2 doesn't really process anything since it is sending NO OPERATION command (and all 24 bits are zero).

    As for pic3, can you share what was the 24 bit content for DAC_2? Kindly make sure to toggle /SYNC after the 48-bit frame is sent and set it low again before the next frame. I would also appreciate if you can also share the /SYNC and /LDAC  signals.

    Cheers,

    Ivan

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