150V Low I Step-Down DC/DC Controller with 100% Duty Cycle Capability

The LTC3894 is a high voltage step-down DC/DC switching regulator controller. It 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 4.5V to 150V and can regulate output voltages from 0.8V to 60V. It offers excellent light load efficiency, drawing only 9μA 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 50kHz to 850kHz with an external resistor and can be synchronized to an external clock from 75kHz to 800kHz.

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 LTC3894 is available in a thermally enhanced 20-Pin TSSOP package with leads removed to accommodate high voltage creepage and clearance requirements.

Applications

* Automotive and Industrial Power Systems

* Telecommunication Power Systems

* Distributed Power Systems

* Wide Operating VIN Range: 4.5V to 150V

* Wide VOUT Range: 0.8V to 60V

* 9μA IQ when Regulating 48VIN to 3.3VOUT

* 16μA IQ when Regulating 12VIN to 3.3VOUT

* Very Low Dropout Operation: 100% Duty Cycle

* Adjustable Input Overvoltage Lockout

* Programmable PGOOD Undervoltage Monitor

* RSENSE or Inductor DCR Current Sensing

* Selectable High Efficiency Burst Mode® Operation or Pulse-Skipping Mode at Light Loads