Buck Controller Peak Current Mode Piecewise Slope Compensation Technology

To improve the switching stability of current-mode controllers and expand the input-output range, a piecewise slope compensation technique is proposed for a Buck converter operating in Continuous Conduction Mode (CCM). This circuit performs slope compensation by sampling peak current information. When the duty cycle is less than 35%, the slope compensation rate is zero. When the duty cycle exceeds 35%, the slope compensation rate varies with the duty cycle. This method eliminates subharmonic oscillations that may occur when the duty cycle is greater than 50% and prevents over-compensation at very small duty cycles. The design and simulation are based on a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.18 \mu ~\mathrm{m}$</tex> BCD process. Simulation results demonstrate that the slope compensation circuit exhibits excellent compensation capability and load-handling performance.