Dear all,

Need some help here ..
I have some doubts regarding DAC by using R-2R ladder.
With reference to the MicroElectronic books by Richard C.Jaeger,
There are differences for output voltage between normal R-2R ladder and inverting R-2R ladder due to the superposition theorem.
From what I know, the difference in these two type is only the switch position. Normal R-2R ladder might lead to linearity error.
Can anyone briefly describe this statement?

If i replace the switch with DIP Switch, that mean it will open circuit when it is not connected to reference voltage, is it okay with this ? Because DIP Switch give the linearity error result that is what the book written Normal R-2R ladder has linearity error.
Can anyone clarify this as well =)

My propose circuit is http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/dac.html (Under R-2R ladder DAC)

Really appreciate your efforts ! =D
Thank you .

 

Hi,

Theres a good video here that might help!

HTH Steve

 

If you use SPST switches, the effect of the op amp input offset voltage will vary as the input code varies.

Also, the settling time will vary as the input code varies. If you are using mechanical switches, this won't be an issue.