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Configuring AD5422 Midscale Voltage output

Hi Team,

I am able to get 0-5V output range with AD5422 DAC, but I want to set the output range in the Midscale range (between 0.5-5V).

I tried to configure CLEAR SELECT and CLEAR bit in the AD5422 Control register but the lowest output value is always 0V instead of 0.5V .

Please suggest to me how to configure the same for 0.5V output?

Best Regards,

Keshava Shreenidhi

  • Hi Keshava, 

    The values issued for the clear function are fixed as shown in table 22 on the datasheet. For unipolar configuration, such as in your case, it can just either be 0V or midscale (2.5V). 

    What is your application here? Why do you need to have the clear voltage set to 0.5V? Is it not possible to just use a data write to the device to set it to 0.5V?

    ~Ian

  • Hi Ian,

    Thanks for your reply.

    No, I don't want to set the clear voltage as 0.5V.

    Our requirement is: for digital input values in the range 0000 to FFFF we should get the DAC output in the range

    (1) 0.5V to 5V. 

    (2) 0.25V to 7V

    (3) 1.3V to 6.3V

    So I thought by configuring CLEAR and CLEAR_SEL I might get the DAC output in those ranges.

    Is there any way I can get these outputs? 

    Thank you,

    Keshava Shreenidhi

  • Hi Ian,

    I am able to get the DAC outputs in those ranges. Thanks for your support.

    I didn't make any hardware changes. Changed some logic in the code.

    Thanks

    Keshava Shreenidhi B

  • Hi Keshava, 

    For some reason, my reply wasn't sent yesterday. I was also going to suggest adjusting your input codes to the dac to match your output ranges requirement. However in this case, your resolution will remain the same regardless of your custom output range. The resolution will be defined by the output range programmed in the DAC. ie. for range 0.25 to 7V, you'll need to select the 0-10V output range of the DAC. The minimum resolution you'll get is based on the 0-10V range, which is ~152uV.

    ~Ian