Using a Low Power MCU to Control Operation Frequency to Increase DC-DC Buck Converter Efficiency in the Light Load

摘要

Step-down DC-to-DC power converters are widely used in electronic modules such as motherboards, Video Graphics Array cards, server power supplies, car chargers, etc. The main purpose of these power converters is to convert high voltage buck into a variety of different voltages for those modules requiring different voltage levels. In this design, the microprocessor control unit (MCU) is used to sense the converter output current and then the MCU is used to control the pulse width modulation (PWM) operating frequency of the converter. This design can adjust the PWM operating frequency with the magnitude of the output current in order to both reduce power loss of the converter and to improve the power conversion efficiency. Our experiments show that the conversion efficiency control can reduce the electronic module's temperature.