Demonstration circuit 2506A is a high voltage, currentmode DC/DC step-down converter featuring the LTC3894.
The board operates from an input range of 6V to 150V, and provides a 5V, 3A output. The PMOSFET architecture allows it to operate seamlessly up to 100% duty cycle, and function as a saturated switch below the regulation threshold. This application has undervoltage lockout programmed for a 6V minimum input to assure adequate gate drive for the MOSFET. It operates at 150kHz and may be synchronized to an external clock. A soft-start feature controls output voltage slew rate at start-up, reducing current surge and voltage overshoot. Burst Mode operation that improves efficiency at light loads can be enabled with a jumper. A power good output signal is provided.
This board is suitable for a wide range of automotive, telecom, industrial, and other applications. The LTC3894 is available in a thermally enhanced 20-pin TSSOP package with skipped leads to accommodate high voltage creepage and clearance requirements. For other output requirements, see the LTC3894 data sheet or contact the LTC factory.