Digitally controlled step-up converter instead of using resistor feedback

[DanioIO]

Hi,
I need to control a output voltage from a step-up converter using a microcontroller is it possible to use a DAC instead of a resistor feedback in this case?

[zapta]

You still need the feedback for the stabilization but you can inject signal from the DAC that influence it. What is your original circuit?

[theatrus]

An op-amp summation stage from the feedback network with your DAC injected is one approach that would work for tweaking the value. Tweaking the ground reference point is another approach (though not directly from a DAC output).

What is your circuit so far?

[DanioIO]

Can this circuit do its job? I want to control LTC3862 which has a feedback reference set at 1.22V.

[theatrus]

Your op amp is missing a feedback network but you have the right idea for a difference amplifier.