MAXREFDES1221

描述

This reference design boosts a single-cell battery voltage to a 10W output using the MAX669 controller in the bootstrapped mode. The bootstrap on the input allows the circuit to continue regulating for very low-input voltages.

This circuit boosts to 12V, 0.833A on the output for a 2.6V to 4.5V input. The MAX669 IC in this design is a constant-frequency, pulse-width modulating (PWM), and current-mode DC-DC controller. It can be used for a wide range of DC-DC conversion applications including step-up, SEPIC, flyback, and isolated-output configurations. Power levels of 20W or more can be controlled with conversion efficiencies of over 90%.

优势和特点

• Tiny 10-pin μMAX package
• Low-input voltage range
• Current-mode PWM and idle-mode operation
• 220μA quiescent current
• Logic-level shutdown
• Soft-start
• High efficiency