>> > Instead of purchasing a DAC just make an R2R ladder network DAC.  We
>> build one in our EE course in second year, it was 16bit accuracy and
>> worked rather well...
>>
>> How did you manage that? Even if you use 0.1% resistors, you can only
>> get 1 part in 1000 accuracy. Sixteen bits needs 1 in 65536 which is 15
>> parts per million. Are there resistors with that accuracy?
>
>
> The best "standard" resistors at Farnell are 0.01%,
> 0.6 ppm/DegC (SMD). That's still 100 ppm, so a 16-bit
> DAC is still "hard" even with these...
>
> And they are $15 - $40 *each* in single quantity... :-)

Wait a minute, you need to read up a bit on R2R ladders if you think you
need .01% resistors to get 16 bit performance. It isn't a walk in the
park, but the tolerance of the resistors in the ladder does not have to be
very good.

-Bob

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