Sometimes I feel that the success that IC vendors have had at packing amazingly good performance and useful features into power-supply regulator ICs — whether low dropout (LDO) or a switcher — has worked against them.
Why? As a result of doing such a good job, these critical components often don't get the attention, consideration, or respect they should. After all, without these regulators, most designs would be struggling, trying to work properly with power rails that had the wrong local characteristics (nominal voltage, noise, accuracy, configuration, etc.), even when sufficient bulk power was available on the board.
Users, in turn, have mixed feelings about these regulator ICs. On one hand, there are so many available that they figure they'll just solve their supply-distribution/delivery problems by dropping these in like popcorn, as needed: end of concern, problems solved. On the other hand, they also can be overwhelmed by the sheer number of regulators out there to choose among, in both linear and switching versions. Why do vendors have to offer so many that you can't decide which is the “right” or “best” one for the application? Who has time to go through all the available ones from any single vendor, let alone multiple credible vendors?
But we are doing what we can to help. We've just posted an online course, Fundamentals of Choosing LDO and Switching Regulators, which looks at these components for regulating low voltages at currents under one Amp: how to evaluate their key parameters with respect to your priorities, what the tradeoffs are, BOM and purchasing issues, and some tools that may help you configure your topology and select actual devices.
The course can help you work your way through the selection tree of many devices. It's free, it's under an hour, and it's online: what's not to like?
Click on the link and sit back; you'll likely get some no-nonsense insights that will help you in your quest for the regulators to select for your design. Since a typical PC board has so many of these “little guys” in use, it's an area where a little more understanding can return solid performance, price, and troubleshooting dividends.