I am trying to wet my feet with switching regulators. Please note I am not an expert on electronics.
Currently, I wish to have an adjustable supply of about 3 - 25 Volts, 5A available across the voltage range. The input to this is 30VDC from a transformer/rectifier at max 7A. The original decision was to use an LM1084 adjustable regulator, and even though it won't be able to supply sufficient power at the lower levels (at Vi-Vo=25V less than 1A), I would know how to use this device. I don't want to switch multiple in parallel.
Now I have looks at the more efficient switching regulators and datasheets on Mouser, but the have a lot of circuitry around them to get right (example circuits for different types of converters), and I'm not sure I understand all the ratings or which circuit I need in the datasheets.
For example, LT's LT1070 datasheet lists the following:
Negative Buck Converter
Positive Buck Converter
Negative Current Boosted Buck Converter
Positive Current Boosted Buck Converter
Negative to Positive Buck/Boost Converter
Positive to Negative Buck/Boost Converter
Voltage Boosted Boost Converter
Current Boosted Boost Converter
Negative Boost Regulator
Negative Input/Negative Output Flyback Converter
Totally Isolated Converter
What would be an "common" adjustable switching regulator that I can control with a potentiometer that would be appropriate for this application, and the appropriate circuit type?
Thank you in advance.
After suggestions of a Prosivite Buck Regulator, I came up with an LM2678. On page 22 of the reference design, there is a reference circuit:
There are also long lists of inductors for L and Schottky diodes for D1 to choose from. I think they recommend 47uH for L. What is the use for D1? Is it a flywheel diode??