Most USB chargers cram a lot of electronics into a mighty small volume, and are built to a price point, meaning that something has to give in the design ... to switch-mode power supply designs ...

[Ben] wanted a switch mode power supply for his breadboard ... switch mode supply achieves compared to linear regulators. This design adds in two capacitors which are suggested in the application ...

Combining a buck-boost topology and Silent Switcher technology brings very low EMI at the highest power-conversion efficiency ...