Linear Technology Corporation introduced the LTC3895, a new high-voltage non-isolated synchronous step-down switching regulator controller that drives a full N-channel MOSFET power stage.
The device's 4V to 140V (maximum 150V abs) input voltage range is designed to operate from high input voltage sources or inputs with high voltage surges, eliminating the need for external surge suppression equipment. When the input voltage drops to 4V, the LTC3895 continues to operate with a duty cycle as high as 100%, making it ideal for transportation, industrial control, robotics, and data communications applications.
At a maximum output current of 20A, the output voltage can be set from 0.8V to 60V, and the efficiency is as high as 96%. With stable output voltage, the device consumes only 40µA in sleep mode, making it ideal for systems that are always on. The internal charge pump can achieve 100% duty cycle operation at low dropout conditions, which is useful when the battery is powered during discharge. The LTC3895's powerful 1ohm N-channel MOSFET gate driver can be adjusted from 5V to 10V, enabling the use of logic-level or standard-level MOSFETs to maximize efficiency.
To prevent high on-chip power consumption in high input voltage applications, the LTC3895 includes an NDRV pin that drives the gate of an optional external N-channel MOSFET. This transistor is used as a low dropout linear regulator to provide the IC. power supply. The EXTVCC pin allows the LTC3895 to be powered by the output of a switching regulator or other available power source, reducing power consumption and increasing efficiency.
