I have been trying to source a Buck/Boost IC to design a circuit for my needs but I'm having a little trouble understanding how I would do this.
I am currently designing a circuit that will provide a regulated 12V output (around 3A max) from either a 12V battery or 12V DC input.
My go-to would be an adjustable linear voltage regulator, but these can only step down to voltage levels that are less than the voltage input (dependant on the dropout voltage of the regulator). As battery voltages will decrease over time (approx 12.65V to 11.9V) the linear regulator would not suffice (Not to mention that 12.65V is within the voltage dropout range of the linear voltage regulator when it is set to output 12V).
I could decrease/increase the input voltage and combine that with a boost or buck/linear regulator to achieve a 12V output but I would prefer to keep the input as 12V.
I found this post (Stabilize 12V to 12V) which recommends a Buck-Boost Converter. This seems like it would work for my application.
I've had a look on RS components through some datasheets but the typical circuit applications either show the IC in Buck or Boost configuration and not as a Buck-Boost. (Example TI MC33063AP)
Therefore, I was just wondering if there were some pointers on how to construct a suitable circuit for this application. For example, some ICs seem to mention PWM control, I assume this would mean I need to include something like a 555 IC to control the buck/boost functionality?
There also seems to be a lot of terminology for Buck-boost (Buck boost switching regulators, Buck boost controllers, Synchronous buck boost etc..) is there a particular type that would be best suited to this application?