CONTROL MODE SWITCHING CIRCUIT FOR SWITCHED-MODE POWER SUPPLY, AND SWITCHED-MODE POWER SUPPLY CHIP

• Main Authors: CHENG, Jiantao, DONG, Yuan, WANG, Yunsong
• Format: Patent
• Language: Chinese; English; French
• Published: 02.07.2020
• 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 control mode switching circuit for a switched-mode power supply, and a switched-mode power supply chip. The control mode switching circuit for a switched-mode power supply generates a drive signal, and comprises a mode switching threshold generation module (1), a negative feedback loop control module (2), and a drive signal generation module (3). The mode switching threshold generation module (1) comprises: a first current source, a first resistor, an equivalent variable current source, and a first operational amplifier, wherein the equivalent variable current source is connected to the first resistor in parallel, and a current of the equivalent variable current source has a positive correlation with an input voltage of the switched-mode power supply. The equivalent variable current source of the present invention is capable of diverting a current from the first resistor, and a current value thereof has a positive correlation with the input voltage of the switched-mode power supply, such that the magnitude