Isolated gate driver adapted for PWM-based switching power supply

• Main Authors: ZHU JING-PENG, XU MING, NAN ZHANG-HE, SUN JU-LU
• Format: Patent
• Language: English
• Published: 14.10.2014
• 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; BASIC ELECTRONIC CIRCUITRY; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; PULSE TECHNIQUE

An isolated gate driver including a driving control circuit, an isolated transformer, an anti-circuit and a secondary processing circuit is provided. The driving control circuit is configured to generate a driving PWM signal for driving a power switch tube. The isolated transformer has a primary winding and a secondary winding. The anti-circuit is connected between the driving control circuit and the primary winding of the isolated transformer, and is configured to suppress a variation of an induced voltage in the secondary winding of the isolated transformer when a duty cycle of the driving PWM signal is sharply decreased. The secondary processing circuit is connected in parallel with the secondary winding of the isolated transformer, and is configured to perform a voltage clamping action on a gate-source voltage of the power switch tube when the duty cycle of the driving PWM signal is sharply decreased.