The AP5100 step-down converter from Diodes has been designed for distributed power applications and features a built-in power mosfet with internal compensation circuitry.

The fixed switching frequency is 1.4MHz.

According to the supplier, with its low series on-resistance power mosfet switch, the converter can deliver a constant current output of up to 1.2A at 90% efficiency over a wide input supply range, from 4.75V to 24V. 
The output is adjustable via a resistor divider, from 0.81V to 15V.

The AP5100 has an enable pin allowing it to be put into standby mode where it consumes 0.1µA.

For more information, see www.diodes.com