My experience with power supplies so far is limited to linear regulators. I am looking to build a 5V charger capable of charging a smart-phone from a variety of battery sources. I'd like the allowable input voltage range to be ~3-15V, a maximum output current of >=1A, and a reasonable efficiency (i.e. not a critical requirement). I'm having trouble finding a part including a reference design that will meet these requirements. I have looked at several boost/buck converters with datasheets showing circuits for either boost or buck, but not both together.
Except, I did find a mention of this one part that seems to do what I want, but I'm not sure this is the best solution: http://www.ti.com/product/lm25118 I also have not been able to figure out how to search for similar parts- i.e. keywords / parameters to use.
I found this thread, How to adjust the voltage of this SMPS? which shows one method. Someone in that thread pointed out that a SEPIC would be a better choice than using two regulators. I found that Linear has a line of SEPICs. This one looked promising http://www.linear.com/product/LT1935 but the datasheet seems to indicate that while the max switching current is 2A, in a SEPIC configuration it can only provide 5V at 550mA off of four AA batteries.
Anyway, I'm guessing this is a mostly solved problem and I was wondering if anyone could point me toward a part, app note, reference circuit, or some search terms that I might be able to work from.