Sanken Electric Co., Ltd.

Sanken Electric Korea Co., Ltd.

Hanju Kang

Shinji Aso

Mitsutomo Yoshinaga

Eunsuk Lee

Masaaki Shimada

Kyusam Choi

Jungyul Kim

Jaekuk Yu

A detector compares a drain voltage with a first threshold voltage and outputs a first detection signal. An ON counter detects a period of time during which a current flows in a switching, counts the period of time based on a predetermined clock cycle. An OFF counter detects a period of time during which a current flow through the body diode in a state where no current flows in the switching circuit, counts the period of time. An off-time setting circuit sets the time to turn off the switching circuit. A first comparison circuit compares the cycle count value with turn off time. A second comparison circuit compares a cycle count value output by the ON counter with a comparison result output by the first comparison circuit and outputs a signal to stop transmitting a PWM signal.

Resonant converter with a synchronous rectifier controller having ontime and offtime counting

A detector compares a drain voltage with a first threshold voltage and outputs a first detection signal. An ON-counter detects a period of time during which current flows in a switching circuit based on the first detection signal, counts the period of time based on a predetermined clock cycle, and outputs an ON-count value. A first comparator receives the ON-count value and an ON-threshold value and outputs a first comparison signal when the ON-count value and the ON-threshold value match. A second comparator receives the ON-count value and a decreased ON threshold value, compares the ON-count value and the decreased ON-threshold value, and outputs a second comparison signal. An ON-mask time adjuster receives the second comparison signal and outputs an ON-threshold value for adjusting a mask time and a decreased ON-threshold value that is less than the ON threshold value.

Switching power supply apparatus

Growing community of inventors

Niiza, Japan

Hanju Kang