60V Low I Step-Down DC/DC Controller with 100% Duty Cycle Capability

The LTC3864 is a robust, high voltage step-down DC/DC controller optimized for automotive and industrial applications. It drives a P-channel power MOSFET switch allowing 100% duty cycle operation. The wide input and output voltage ranges cover a multitude of applications. This device has been verified with the failure mode and effects analysis (FMEA) procedure for operation during failure conditions.

The LTC3864 offers excellent light load efficiency, drawing only 40μA quiescent current in a user programmable Burst Mode operation. Its peak current mode, constant frequency PWM 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 750kHz.

The LTC3864 offers programmable soft-start or output tracking. Safety features include overvoltage protection, overcurrent and short-circuit protection including frequency foldback and a power good output signal.

The LTC3864 is available in thermally enhanced 12-Pin MSOP and 3mm × 4mm DFN packages.

APPLICATIONS

* Industrial and Automotive Power Supplies

* Telecom Power Supplies

* Distributed Power Systems

* Wide Operating VIN Range: 3.5V to 60V

* Wide VOUT Range: 0.8V to VIN

* Low Operating IQ = 40μA

* Very Low Dropout Operation: 100% Duty Cycle

* Strong High Voltage MOSFET Gate Driver

* Constant Frequency Current Mode Architecture

* Verified FMEA for Adjacent Pin Open/Short

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

* Programmable Fixed Frequency: 50kHz to 850kHz