Electronic – Best way to power a 3.3V circuit from 3.3V-to-5.0V source


I'm working on an add-on board that needs 3.3V power (~500mA) and should take power from its host board. The host can operate at 3.3V or 5V and I'd like to avoid using jumpers that would require the user to select the host power.

I was thinking of using a boost converter to generate, say, 6V from the host board and then use a buck regulator to bring it back to 3.3V. Is there a better approach?

Best Answer

Maybe a buck-boost? Like this for an example: http://www.linear.com/product/LTC3536

The LTC®3536 is an extended VIN range, fixed frequency, synchronous buck-boost DC/DC converter that operates from input voltages above, below or equal to the regulated output voltage