LM25088,pdf datasheet (Wide In

The LM25088 high voltage non-synchronous buck controller
features all the necessary functions to implement an efficient
high voltage buck converter using a minimum number of external
components. The LM25088 can be configured to operate
over an ultra-wide input voltage range of 4.5V to 42V.
This easy to use controller includes a level shifted gate driver
capable of controlling an external N-channel buck switch. The
control method is based upon peak current mode control utilizing
an emulated current ramp. The use of an emulated
control ramp reduces noise sensitivity of the pulse-width modulation
circuit, allowing reliable control of very small duty
cycles necessary in high input voltage/low output voltage applications.
The LM25088 switching frequency is programmable
from 50 kHz to 1 MHz.