The LT3682 is a new 1A buck regulator that overcomes the duty cycle limitation by monitoring the current through the external catch diode, and delaying the generation of new switch pulses if this current exceeds a defined value. The LT3682 safely accommodates output shorts and overload conditions.
This document describes a design solution for using buck regulators in applications where output short-circuit and overload conditions occur. It explains that traditional regulators may fail because the required duty cycle to control inductor current can be lower than the minimum duty cycle at full speed, necessitating a reduction in switching frequency.
The LT3682 accepts transients up to 60V.
The device features an adjustable switching frequency from 250kHz to 2.2MHz.