CM1821hf is a 300mA, synchronous step-down integrated buck DC-DC converter IP core optimized for 3MHz fixed frequency operation and designed for CV018MS (0.18μm HV). The input voltage is fixed in 5V ...

[Great Scott] should win an award for quickest explanation of a buck converter. Clocking in at five and a half minutes, the video clearly shows the operating principles behind the device.

[Julian Ilett] recently posted two videos that fit this description. He built a buck converter and made measurements about its efficiency using different configurations. The test setup is simple.