Effect of OP amp change

Hi, 

Depends on where you place the opamp on your DAC circuit. Usually, the input bias current can be associated with the respective loadregulation error, either it be at the DAC output or the reference output. 

Regards,

~ian

Dear ian san,

Thank you for reply.
I see.
I tried "Precision DAC Error Budget Caluculator-BETA", here is its capture.

Best regards,

Sachiko Kanzawa

Hi Kanzawa san, 

Great find, I was about to recommend using this tool. Looks like the AD826's input bias current is quite large resulting in a huge increase in ppm error. I suggest looking for other amps. The AD648 looks like a good choice. 

Regards,

~ian

Dear ian san,

Thank you for advice.
I'll consider it.

Best regards,

Sachiko Kanzawa