Switching power supply control method and circuit as well as switching power supply with switching power supply control circuit

• Main Authors: HANG KAILANG, SUN LIANGWEI
• Format: Patent
• Language: Chinese; English
• Published: 12.02.2014
• 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

The invention relates to the field of electrons, and discloses a switching power supply control method and circuit as well as a switching power supply with the switching power supply control circuit. The method comprises the steps of generating theoretical conduction time signals according to the input voltage and the output voltage of the switching power supply; generating ripple voltage signals; ensuring that the voltage value of the ripple voltage signals is a preset fixed value when the power switch tube of the switching power supply is turned on, and the voltage value of the ripple voltage signals is linearly descended when the power switch tube is turned off; obtaining voltage regulating signals according to output voltage sampling signals and the ripple voltage signals of the switching power supply; comparing the voltage regulating signals with preset second reference signals, outputting level regulating signals; generating practical conduction time signals according to the level regulating signals and