An Adaptive Slope Compensation Circuit for Buck DC-DC Converter

An adaptive slope compensation circuit applied to buck DC-DC converters is presented in this paper. Based on the basic theory of slope compensation, the conditional expression of the loop stability is gained. According to the conditional expression, using feed-forward control of the input voltage and the feed-back control of the output voltage, the slope compensation is provided with adaptivity, which makes the system stable with the variation of duty cycle all the time. In addition, the proposed slope compensation circuit improves the system's loading capacity and transient response in high duty cycle. The circuit is designed on the base of Samsung BCH4 process, and its performances have been verified by Hspice simulation.