Ripple-Based Adaptive Constant On-Time Control with Adjustable Virtual Ripple for Buck Converter

Ripple-based adaptive constant on-time (RBACOT) control with virtual ripple are conceptually simple, fast dynamic transient responses at lower duty cycle application, and lower component count. This control schema solves instability issue of sub-harmonic oscillation when ceramic capacitors are used. These characteristics make the regulators well-suited, especially for power management applications in portable electronic devices and computers. However, this control schema has some drawbacks of poor dynamic transient response at specified duty cycle range and inherent output voltage offset problem. This paper discussed mentioned shortcomings. A new method called ripple-based adaptive constant on-time control with adjustable virtual ripple was proposed to improve dynamic transient response. Simulation and experiment results show that the proposed concept achieved fast dynamic transient response.