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DAC7678: resolution / accuracy with +3.3V supply

Ue
Genius 16285 points
Part Number: DAC7678
Other Parts Discussed in Thread: DAC60508

Hi all

My customer is evaluating the DAC7678 and they would like to power this DAC from a +3.3V.

What accuracy / resolution can they expect ?

Will they get lower accuracy / resolution compared to powering from +5V or +5.5V ?

They need to generate a 0 ... 1V signal with 12 bit resolution.

Please comment as to what to watch out for.

Thank you and best regards

Ueli

  • 0
    TI__Guru 52663 points

    Hi Ueli,

    If they power the device with 3.3V and use the internal reference, they can expect linear behavior as guaranteed by the specification table until they start to approach the 3.3V output limitation.  I expect that they would get linear operation until about 3.1V in this case, depending on the current load.  The 0-V to 1-V range will be fine, but you will be using only 20% of the output (<10bit resolution in that range). 

    You could also look at the DAC60508, which has a 1.25V output range.

    Thanks,

    Paul

  • 0 in reply to Paul_Frost
    TI__Genius 16285 points

    Hi Paul

    Thank you for the quick reply.

    My understanding is the customer will scale-down the 0 ... 3.1V to the required 0 ...1V so that they should still get the full resolution.

    I also pointed to the DAC60508 but the customer prefers I2C over SPI. They are using an ASIC with integrated uC-core where they have no spare SPI available.

    Best regards

    Ueli