ON TIME SAMPLING PREVENTION

摘要

An exemplary controller for a power converter includes a feedback sampling circuit, a driving logic circuit and a false sampling preventing circuit. The feedback sampling circuit samples a feedback signal received from a terminal of the controller and generates a sample signal to represent the value of the feedback signal through a coupling operation. The driving logic circuit is coupled with the feedback sampling circuit to control a power switch to adjust an output of the power converter in response to the sample signal. The false sampling preventing circuit receives a sampling terminating signal to indicate the time at which a sampling process for the feedback signal is terminated through a coupling operation. The false sampling preventing circuit is further coupled with the driving logic circuit in order to prolong an off time of the power switch until the sampling terminating signal indicates that the sampling process for the feedback signal has been terminated by the feedback sampling circuit.