AD5684 Default values for register settings at startup

Hi Hiroyuki.D ,

We'll be checking this query shortly. Thanks for your patience.

Best Regards,

Den

Hi Hiroyuki.D ,

The AD5684 indeed defaults to Standalone mode with a gain of 1 upon startup as stated by the datasheet. However, the datasheet does not provide explicit information about the default states of the power-down modes (PDx0 and PDx1). Based on my laboratory testing (using EVAL-AD5686R), they appear to be set to "Normal Operation" upon power-up (PDx0 = 0, PDx1 = 0). It's a good practice to set all the necessary registers to your desired configuration upon power-up or before performing read/write. This ensures that the device operates according to your specific requirements, such as power-down modes, gain settings and even the reset select pin(low -> zero scale or high -> midscale, output remains powered up at this level until a valid write sequence is made to the DAC).

Best Regards,

Den

Hello Den,

Thank you very much for your reply. 

"It's a good practice to set all the necessary registers to your desired configuration upon power-up or before performing read/write."

=> Is it correct to understand that if I don't put this into practice, it will no longer be possible to define whether it starts up at L or H as AD5684?
Since there is no definition whether it starts up at L or H, is it okay to assert that it is not a problem with AD5684?

Regards,

Hiroyuki

Hi Hiroyuki.D ,

"Is it correct to understand that if I don't put this into practice, it will no longer be possible to define whether it starts up at L or H as AD5684?"

Registers have definite values upon startup, as mentioned AD5684 defaults to Standalone mode, gain of 1 and power-down mode set to "Normal Operation" (PDx0 and PDx1 = 0) with DAC registers set to 0 as well.

"Since there is no definition whether it starts up at L or H, is it okay to assert that it is not a problem with AD5684?"

Every time the DAC power cycles it resets the register to the default values stated above. You may control the output voltage upon power up by tying the Reset Select pin to either GND or VLOGIC to achieve either zeroscale or midscale output respectively.

Best Regards,

Den