I know that the opposite is possible i.e. using 2 DAC's to get a higher quality output, but is it possible with ADC's?
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\$\begingroup\$ And your premise isn't correct either; you can't combine two DACs to double their resolution. \$\endgroup\$– user39382Commented May 8, 2017 at 22:52
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\$\begingroup\$ @duskwuff If you check Microchip mcp4822 there is documented an application to get a 24-bit DAC by combining 2 12-bit channels of a DC. \$\endgroup\$– John AmCommented May 8, 2017 at 23:04
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\$\begingroup\$ To do that with DAC or with ADCs requires that the device dealing with the most significant bits has an accuracy equal to of the LSB of the whole system - most ADC/DAC only have an accuracy of about 1LSB or slightly better referenced to its own bit length. \$\endgroup\$– Kevin WhiteCommented May 8, 2017 at 23:45
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\$\begingroup\$ I assume you are talking about ww1.microchip.com/downloads/en/DeviceDoc/20002249B.pdf That is not what you call a well-thought-out app note. The specification of "a digital value in the range 0-4096" ought to be a tipoff. What the app note fails to mention is that the two resistors must have a resistance ratio accurate to the unit DAC dynamic range. So, even for the 1000:1 ratio implied, this means resistors matched to 0.1%, and a full 24-bit unit would require matching to 0.024%. Worse, the interpolation is not consistent, but varies with the level of the major DAC. \$\endgroup\$– WhatRoughBeastCommented May 9, 2017 at 3:01
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1\$\begingroup\$ Just over-sample thousands of times and you'll make a 20 bit ADC from a 10 bit ADC. You don't need multiple ADCs to do this. \$\endgroup\$– Andy akaCommented May 9, 2017 at 7:30
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I know that the opposite is possible i.e. using 2 DAC's to get a higher quality output, but is it possible with ADC's?
generally no.
that means in some cases it is doable. For example, for adc's with external reference.
