Power by Linear™ / Analog Devices’ LTC3894 is a high voltage step-down (buck) DC/DC switching regulator controller. This controller drives a P-channel power MOSFET switch allowing 100% duty cycle operation. It enables a low part count, simple, and robust solution for high reliability, high voltage applications.

The LTC3894 operates over a wide input voltage range from 4.5 V to 150 V and can regulate output voltages from 0.8 V to 60 V. It offers excellent light load efficiency, drawing only 9 μA quiescent current while regulating the output voltage with no load. Its peak current mode, constant frequency architecture provides for good control of switching frequency and output current limit. The switching frequency can be programmed from 50 kHz to 850 kHz with an external resistor and can be synchronized to an external clock from 75 kHz to 800 kHz.

The LTC3894 offers programmable output voltage soft-start or tracking. Safety features include overvoltage, overcurrent, and overtemperature protection with a power good output monitor with adjustable threshold. The controller is available in a 20-pin TSSOP package with leads removed to accommodate high voltage creepage and clearance requirements. The LTC3984 was designed for automotive, telecom, and industrial power supplies.