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Cascading two AD55x7's for bit resolution doubling

Is it possible to use one AD55x7 DAC as reference source for second one to produce higher bit resolution? What drawbacks this solution may have?

  • Hi,

    That is an interesting thought. Are you planning on a full +/- Vref input +/- Vref 2x output? In theory, this is possible but this is not usually done in practice. Cascading two DACs has their own drawbacks:

    • The noise of the first DAC will be added to the second DAC which will result in higher noise levels.
    • Output slew rate of the first DAC should be taken into consideration because the output of the first DAC will be the reference of the second DAC. Note that the value of the first DAC must have settled to its desired value to be able for the second DAC to produce the correct voltage level.
    • The AD55X7 would require a couple of op amps so cascading them together would require you to have at least four additional components.

    If you would share your application or motivation for a higher resolution DAC, we may be able to recommend a proper DAC that would match your application needs.