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

• Main Authors: Kang, Hanju, Lee, Eunsuk, Aso, Shinji, Shimada, Masaaki, Yoshinaga, Mitsutomo, Kim, Jungyul
• Format: Patent
• Language: English
• Published: 22.10.2024
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

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.