[sdiy] discrete DAC accuracy

[Fredrik Carlqvist]

Hello list!

I'm trying to calculate the absolute error of a discrete R-2R 16-bit DAC. If
the resistor tolerance is 2%, is then the overall accuracy 2% for any binary
code? At least it seems so in the 3-bit case. I don't have the tools for the
16-bit case.

This should also imply that the maximum relative error between two
consecutive binary codes is 4% since each code has a maximum absolute error
of 2% and two consecutive codes can have opposing errors (as 0x8000 and
0x7fff). Am I right? 

This is of course not accurate enough for a VCO control voltage, but should
be ok for a VCA, don't you think?


Fredrik C