ACTIVE CLAMP FLYBACK CONVERTER CAPABLE OF SWITCHING OPERATION MODES

• Main Authors: TSAI, Meng Jen, CHEN, Yao Tsung, CHANG, Chih Chi
• Format: Patent
• Language: English
• Published: 19.03.2020
• 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 power converter using an active-clamp flyback topology has a low-side switch, a high-side switch and a control circuit. The low-side switch connects a primary winding of a transformer to an input ground line, and the high-side switch is connected in series with a capacitor to form an active-clamp circuit connected in parallel with the primary winding. The control circuit provides high-side and low-side signals to the high-side and the low-side switches respectively, in response to a current-sense signal and a compensation signal. The control circuit is configured to operate the power converter in one of operation modes including a complementary mode and a non-complementary mode. When operated in the complementary mode, the high-side signal and the low-side signal are substantially complementary to each other, and the control circuit exits the complementary mode in response to the current-sense signal to enter the non-complementary mode.