How to Improve Buck Converter Light Load Efficiency with an LDO
By Michael Hartshorne @ digikey.com:
Designing a DC/DC converter that only consumes micro amps of current at no load can be compared to fueling a muscle car with lighter fluid – you may get it to work, but it won’t be easy. High efficiency at full load currents is commonplace in most modern DC/DC converters; however, achieving high efficiency when the load is disabled or disconnected is still a difficult and/or expensive task.
How to Improve Buck Converter Light Load Efficiency with an LDO – [Link]