High Resolution DAC

[Oliver Dial]

Hi! I'm looking for a high resolution (ideally 24 bit) DAC to use in a
low drift DC voltage source. I don't believe a sigma-delta converter
is appropriate for this job (although perhaps someone could convince me
otherwise). Does anyone have any suggestions? I've checked with my
usual suspects (Analog, TI/Burr-Brown, Maxim), and haven't seen
anything that looks appropriate.

 

[Marc Guardiani]

Hi! I'm looking for a high resolution (ideally 24 bit) DAC to use in a
low drift DC voltage source. I don't believe a sigma-delta converter
is appropriate for this job (although perhaps someone could convince me
otherwise). Does anyone have any suggestions? I've checked with my
usual suspects (Analog, TI/Burr-Brown, Maxim), and haven't seen
anything that looks appropriate.

I don't think you're going to find anything but sigma-delta ADCs at
this resolution (for any sort of reasonable price anyway). Look at ADI
again. They have 24-bit ADCs made for measuring DC all the way up to
multi-megahertz sampling ones.

Marc

 

[Marc Guardiani]

this resolution (for any sort of reasonable price anyway). Look at ADI
again. They have 24-bit ADCs made for measuring DC all the way up to
multi-megahertz sampling ones.

Marc

My bad... I read the original post too fast and took DAC for ADC. ADI
probably still has what you're looking for, but I am less familiar with
their DAC offerings.

Mea culpa,
Marc

 

[Jon Elson]

Hi! I'm looking for a high resolution (ideally 24 bit) DAC to use in a
low drift DC voltage source. I don't believe a sigma-delta converter
is appropriate for this job (although perhaps someone could convince me
otherwise). Does anyone have any suggestions? I've checked with my
usual suspects (Analog, TI/Burr-Brown, Maxim), and haven't seen
anything that looks appropriate.

This is 1 part in 16.7 million! Do you actually need that resolution, or
that accuracy? If you need the accuracy, then you are going to find this
assignment real difficult. Everything in the main signal chain is going
to have to be stable to that level. If this were a 10 V max power supply,
then the output would have to be stable, or accurate, to half of a
microvolt!
You won't even be able to breath on the thing without inducing
thermoelectric
voltages that swamp that by an order of magnitude.

Jon