Variable Step-Size Switching Frequency Modulation for Synchronous Buck Converter

A variable step-size switching frequency selection algorithm with fast convergence performance for power converters is presented in this paper. The algorithm can automatically track and detect the optimal switching frequency for a DC-DC converter in order to achieve the highest possible power conversion efficiency. This technique is theoretically analyzed and developed based on synchronous buck converter loss model and its behaviors. A digital control system is designed to apply the selected optimal switching frequency to modulate the PWM duty cycle accordingly. An experimental prototype is built to verify the proposed algorithm and validate the theoretical efficiency improvement.

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