Extend low-output-voltage switching regulator's input range

摘要

Internal operating voltages in electronic devices continue to decrease, but input-source voltages don't change. As the difference between input and output voltages increases, so does the improvement in efficiency that a switching regulator offers. Unfortunately, as a switched-mode step-down converter's output voltage decreases, the decrease imposes limitations on the circuit's input-voltage range. This Design Idea shows how to extend a low-output-voltage step-down converter's input-voltage range.