SYSTEM METHOD AND APPARATUS TO TRANSITION BETWEEN PULSE-WIDTH MODULATION AND PULSE-FREQUENCY MODULATION IN A SWITCH MODE POWER SUPPLY

摘要

A switching mode power supply (SMPS) can transition between pulse-frequency modulation (PFM) control or pulse-width modulation (PWM) control for control of the SMPS according to the load current, Thereby achieving optimized efficiency over time. Accurate, smooth, and smooth transitions between PFM mode operation and PWM mode operation occur at the preset load current (s), PFM operation improves efficiency during light load conditions, and PWM is more efficient at heavier load currents Good efficiency is obtained. This is advantageous for battery powered products, thereby extending the time to use until battery replacement or recharging is required.