You don't need to worry about using 5V logic signals to control the DAC powered by 10V. The 5V digital IO lines are just being used to open and close digital switches in the DAC. These switches are used to select the taps in the R2R ladder network.then i am now looking at the output values to the DAC:
which reminds me, making a 10V reference, the digital outputs are 0 and 5V right?
hgmjr