Well, this is annoying. I have some little power #modules (bought on #AliExpress, natch) that were advertised as automatic boost/buck converters. Input from <4V to >30V, output from 1.25V to 35V. They're based on the XL6009 switching converter, which supports auto-buck-boost as one mode. But they appear to use it in boost-only mode. The output voltage can not go below the input as far as I can tell. From the datasheet, it looks like that's because the auto-buck-boost config requires a few more components, plus a transformer instead of a simple inductor, which is probably the main reason (BOM). The listing just seems to be ... wrong. Annoying. #seller #SellerDescription #YumCha #Chinesium #BuckConverter #BoostConverter #AutoBuckBoost #BuckBoost #electronics #hobby