The TI UCC28880 is a great monolithic buck regulator solution for designs requiring a low-power (<300mA), non-isolated, universal voltage solution. And it's cheap too: a dozen total parts count for under $5 in unit quantities.
It isn't perfect though. In 'high side' configuration the feedback pin isn't continuously sampled and that leads to more noise in the output. The 'low side' configuration eliminates this through the use of a level shifting transistor to drop the sense voltage to the regulator's ground reference. Unfortunately this introduces a significant (>1V variation) temperature coefficient to the regulated output.
This project demonstrates a simple solution to temperature stabilize the output to within +/-200mV of the set output voltage over an operating temperature range of -20 - +80C.
The PDF in the files section contains the full technical explanation and schematics.