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DAC8760: Can't able readback from DAC8760 - reg

Part Number: DAC8760

Hello All,

        I'm working with DAC8760 in newly designed Hardware board. I'm trying to reset the chip by writing 0x560001 and configuring control register to 10v range

0x553001. I was using same steps as AD5422 chip's register programming as I couldn't find programming steps anywhere in DAC8760 data sheet.

I was trying to read back the wrote values data register by writing 0x200001 there was no response from the chip, Also Output stays at 0v

but I was able to read the response of Control register and Configuration register.

I wrote 0x553001 and read back 0x3001 by writing command 0x020002.

I wrote 0x570007 and read back 0x07 by writing command 0x02000B.

Even I could able to read the status register value by writing 0x020000 and I got 0x00.

Do I need to issue any additional command to read configuration register?

Please find the analyzer snips.



  • Hi Naveen, 

    Joe will be able to review this on Monday. 


    Katlynne Jones 

  • Naveen,

    I'm not sure what is wrong with the read out of the DAC. Looking at your SPI communication, it looks like you have it set up correctly and the device is giving correct readout for other registers.

    However, the DAC Data register is a little different than the other registers, so there might be something different written into the Data register than what it read out. First, I would make sure that the DAC output is enabled (through OUTEN bit in the Control Register). Then I would measure the reference voltage can be seen at the REFIN pin just to make sure it is there and is correct.

    The DAC data register that you read from is the register with the code that directly sets the output of the DAC. However the code in the DAC data register that you write to is modified to get the data sent to the DAC. This is the basic diagram for the DAC data.

    This diagram omits any affect from the slew rate function. The code read from the DAC data is also modified when the slew rate function is enabled. When the DAC takes the intermediate steps in slew rate mode, the read from the DAC data is the code at the time of read during the slew rate transitions.

    Because the DAC data read can be modified, I would make sure the output is enabled, disable the slew rate function, and not use the calibration registers. Then I would check the output of the DAC with different codes.

    Joseph Wu

  • Hi Joesph, 

          I see the connection line from Microcontroller to DAC8760's Clear pin was held high so the data written was erased.

    I changed the state of pin that controls this DAC's Clear pin. This resolved the issue.



  • Naveen,

    I'm glad you figured that one out! Thanks for letting me know.

    Joseph Wu