Hello

I am designing a DC-DC converter based on LM2673 that can be controlled through a microcontroller and I would appreciate if someone can review my circuit or provide any tips.

One circuit is buck and the other is buck-boost, I have 20V power source and I would like the output to be adjustable from ~1.5 to 18 and the other from -18 to ~-1.5.
LM2673
DS4432
LMV321

My calculations for R0A and R0B from DS4432 datasheet pages 8-9:
for Vfb= 1.21 and Vout=18:
R0B=0.072 x R0A
100uA = IR0B - IR0A
I got: R0A=155.5Ω and R0B=11.2Ω

 

I did not visit the data sheets because it appears that the question would be related to the schematics shown in your post. And I do not find R0B or R0A on the circuits shown here. So it is not really clear just what the questions are. And the "design" does not really look complete.
My suggestion is to run a simulation of the various sections of the circuit, and let us know what appears.

For a detailed engineering evaluation professional charge rates would apply.