dc/dc converterpower electronicspower supplyswitch-mode-power-supply
I want to make a DC/DC supply that outputs between 10V and 28V from a 12V input, the system will need to output up to 20W. Should I use a digipot to adjust the feedback voltage divider, or are there more elegant ways to approach this?
Cost is not an issue.
Here is one approach that might be suitable as is or with slight modification.
What you need to do is to look up single voltage operation for op-amps, and see what you need to do. Hint: It does involve a voltage divider, but not powering the amp.
Here is an example of a 741 running on a single voltage:
Best Answer
Linear makes an IC for this that I've used:
It is a current source/sink and can be used on any DC DC converter with a voltage feedback control and a voltage feedback range from 0.4V to 2V, it's only 7-bit so it doesn't give great granularity on voltage control, but it lets you adjust levels and it has two gain modes.
Another thing is if you wanted to roll your own current source/ sink with a DAC then you could also do better than this. Otherwise stick to a digipot (which could have it's own set of problems).