Patent ID: 8134397
Filing Date: 2012-03-13
Classification: H02M,H03K,Y02B

Abstract:
1. A minimum leading edge blanking (MLEB) signal generator, adapted for receiving an externally inputted error amplification signal and a current sensing signal, for generating an MLEB signal, the MLEB signal generator comprising: a buck unit, receiving the error amplification signal, and generating a reference blanking signal, wherein a voltage of the reference blanking signal is smaller than a voltage of the error amplification signal, and a difference between the voltage of the reference blanking signal and the voltage of the error amplification signal is a first voltage difference; and a signal generation unit, receiving the reference blanking signal, and generating the MLEB signal according to the current sensing signal, wherein the MLEB signal has a width, wherein at a beginning time, the current sensing signal has a peak voltage at a high level, and the current sensing signal drops down to a first voltage along a timeline, and then the current sensing signal rises up from the first voltage along the timeline, wherein a time point at which the voltage of the current sensing signal is equal to the voltage of the reference blanking signal is referred as a first time, and a time length from the beginning time to the first time is the width of the MLEB signal, wherein the voltage of the current sensing signal is smaller than the error amplification signal during the time length, and when the voltage of the current sensing signal is greater than the voltage of the error amplification signal at a time outside the width of the MLEB signal, the current sensing signal is refreshed by an external unit to a first low voltage, wherein the first low voltage is lower than the voltage of the error amplification signal.