[sdiy] DIY Parallel DAC

[David G Dixon]

> You can drive an R/2R ladder from a CMOS buffer or a register 
> such as 74HCT377. Make sure the IC has its own well 
> decoupled/stabilized voltage rail and use large resistors 
> (50..100k or so) to minimize the influence of the output 
> resistances which can be up to ca. 70 ohms. With some 0.1% 
> resistors for the most significant bits you could get around 
> 8 bit accuracy.

...or use the smaller resistances but drive the ladder with a unity gain
buffer.