MAX5035,pdf datasheet (Step-Do

The MAX5035 easy-to-use, high-efficiency, high-voltage,
step-down DC-DC converter operates from an
input voltage up to 76V and consumes only 270μA quiescent
current at no load. This pulse-width modulated
(PWM) converter operates at a fixed 125kHz switching
frequency at heavy loads, and automatically switches
to pulse-skipping mode to provide low quiescent current
and high efficiency at light loads. The MAX5035
includes internal frequency compensation simplifying
circuit implementation. The device uses an internal lowon-
resistance, high-voltage, DMOS transistor to obtain
high efficiency and reduce overall system cost. This
device includes undervoltage lockout, cycle-by-cycle
current limit, hiccup mode output short-circuit protection, and thermal shutdown.