A Detection Circuit for Improving the Unloading Transient Performance of the COT Controller

Fast load transient response and high light-load efficiency are two key features of the constant on-time (COT) control technique that has been widely used in numerous applications, such as for voltage regulators point-of-load converters. However, when step-down occurs during an interval, COT controller cannot respond until interval expires. This delay causes additional output overshoot, resulting unloading performance limitation. To eliminate improve controller, a detection circuit is proposed based on capacitor current (CC-COT) control. In circuit, monitored by comparing measured with preset threshold voltage. Once monitored, promptly truncated switch turned off. With CC-COT-controlled buck converter can monitor without any obtain less overshoot interval. PSIM simulations employed to demonstrate feasibility circuit.