I have some question about AD5412
As i see in the datasheet i can connect "Io" and "Vo". just need a buffer .
your recommended buffer is Dual Op-amp .
I don't need bipolar output range (-5~+5 ,-10~+10) because i don't have dual power supply on my board.
So i have to use single supply op-amp .
As you know most of the single supply opamp that have low offset are very expensive .
Could i use an ordinary (not low or ultra offset) like lm358 as buffer ?(i have tested in zero input out put is about 13 mv).
Could i Connect "io" to "Vo" even when i use Boost ?
Yes, Vo and Io can still be shorted in the manner you have sketched, when the external boost transistor is used.
You might also find the following App Note relevant to your design: