Pulsed loading conditions and abnormal disturbances within the electrical systems found in industrial, vehicle, avionic and other harsh environments can induce wildly varying voltage transients (surges) on what is nominally a 24VDC or 36VDC distributed bus. The disturbances can be between a millisecond to a minute in length, with excursions reaching (or exceeding) 38V and falling below 6V. The severity rating often becomes more of a concern at higher input voltages. The LTM4641 challenges this notion by protecting the load from seeing excessive voltage stress, even when its high side switching MOSFET is short-circuited.
The LTMŽ4641 is a 10A switch mode step-down DC/DC ėModuleŽ regulator with advanced input and load protection features. Trip detection thresholds for the following faults are customizable: input undervoltage, overtemperature, input overvoltage and output overvoltage. Fault conditions can be set for latchoff or hysteretic restart responseor disabled. Included in the package are the switching controller and housekeeping ICs, power MOSFETs, inductor, overvoltage drivers, biasing circuitry and supporting components. Operating from input voltages of 4V to 38V (4.5V start-up), the device supports output voltages from 0.6V to 6V, set by an external resistor network remote sensing the point-of-loads voltage.